test test 4000 + Coupe GT
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  • Frequently Asked Questions (FAQ), Procedures and Resources, DIY, etc.
    Posted by: Pre95 (1154) on 2011-08-02 11:10:25

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    This is how it works: Basically we put a short article or links to good posts / articles as replies to this thread. You can upload images for free here on QuattroWorld Images.QuattroWorld.com and PDFs or other documents for free at Free File Hosting.net and attach them to your post. Please follow the structure of the thread.

    Also if you are about to type a comprehensive answer to someones question, type it in the FAQ thread list below this post or make a link to it in the FAQ thread. Always check to see if a thread has already been started in the FAQ.


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    To find things, either browse down the list or if you want something more directed, use your browser's "FIND IN PAGE" feature (normally Ctrl+f).

    Original FAQ start thread posted in UrS forum by EDIGREG. Signature begins here:
    • Quattro GT firing order...
      Posted by: Chalito (90642) on 2016-03-22 02:26:03

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      Can anyone tell the firing order of an 83 Quattro GT please, thanks
    • - 4k / CGT Forum Specific -
      Posted by: Pre95 (1154) on 2012-07-26 23:27:34

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      • HTML To post images (or multiple images) on your thread.
        Posted by: Pre95 (1154) on 2013-03-23 18:55:40

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        I personally like to use HTML when posting images on KAWF, and figured posting here might ease the pain for some folks trying to get their images up. You can cut & past what I have below and replace URL with the URL of your image.

        <IMG SRC="URL">

        You can repeat the code as many times as you'd like to post multiple images. Remember, sites like Photobucket will give your image a URL ending in .jpg.HTML. If your image URL ends in HTML it will likely not show. To avoid this, right click on the photobucket image while on the photobucket website and click "View Image". This should take you to the correct url ending in .jpg, .gif, etc. showing the image by itself.
    • Parts substitutions
      Posted by: blewtoon (989) on 2012-02-10 20:40:11

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    • - Turbo Convert Specific -
      Posted by: Pre95 (1154) on 2011-12-14 18:15:20

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    • - Braking -
      Posted by: oldsklaudidub (5496) on 2011-12-12 23:41:47

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    • - General Information -
      Posted by: Pre95 (1154) on 2011-12-12 17:32:52

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      • ETKA
        Posted by: blewtoon (989) on 2012-01-03 23:39:55

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      • 4000 4 cyl and 5cyl... a brief history!
        Posted by: Whitjr (3261) on 2011-12-15 14:24:29

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        I started this article as a discussion of the differences inbetween the 4 cyl 4ks and the 5 cyl 4ks, as I am one of the few [the proud] 4 cyl owners on this forum. However, in the interests of accuracy I began researching all sorts of things, and decided to post them, into this article, so the original article became a more extensive and informative one.

        Besides the obvious lack of a 5th cyl, there are numerous differences. The engine compartment is very very similar in size to both models, and the trannys are different. I don't know of any 4 cyl models that are quattro. Nonetheless the traction in this car is very very good, expecially with the addition of a rear sway bar. [I've driven mine is all kinds of weather, snow, ice, etc... and never ever gotton stuck : when I surely would have in a Buick!] There are differences in the dash instrumentation below the radio, having oil/temp/and wattage gauges in place of the differential panel. Dash signeage is also different. Depending on what the purchaser wanted, heated electric seats were available, and varried from car to car. Leather seating was common, as well as cloth. All Coupes and Coupe Quats have big differences from the rear, being a 3 door coupe [rear hatch] and usually had a wing coming off the just above the rear lights. These cars are usually 5 cyl models. Side signage varried with many quat models having the sport audi rings, rear signeage designated the model as well.

        Since the cars were of similar style, many parts could be used in the different models: body trim, dash components, shifters, CIS and injectors, interior seating, and stereo space could be interchanged from car to car. this makes the mods available for these cars many and varried... according to what you want to spend.

        A brief history:

        --1979: 1.6L 4-cylinder with 4-speed manual transmission, both in two and four door versions. A two-door, 5-cylinder model was later offered, with a 5-speed (Designated as the 4000 5+5 in 1980).
        --In 1981 the displacement of the 4-cylinder was increased to 1.7L, and a 5-speed maunal transmission was made standard. The 5-speed models often carry the 4+E badge that signifies 4 normal speeds plus an economy gear. This was a wide ratio 5-speed box. A 5-cylinder model with automatic transmission was also added. The Audi Coupe was also introduced in 1981 with a 5-cylinder engine.
        --In 1982 they added the "S" designation, and dropped the 5-cylinder models, I don't know of a good reason for the additional "S", except that perhaps Audi wanted to designate the additional standard features in the newer models. A diesel and turbo-diesel model was available in 1982 and 1983, but proved to be unpopular.
        --In 1984 the 4-cylinder displacement was increased again to 1.8L (the GTI engine). Also, the 4000S quattro (with all wheel drive and a 5-cylinder engine) was also added.
        --In 1985 all 4000/Coupe models received extensive styling changes in the front grille, lights, bumpers, trunk, and interior. The 1.8L engine had much higher compression ratios, and also received the knock-sensing ignition system. A close-ratio 5-speed transmission was standard. In 1986 the 4000CS was a special model to commemorate the 100th anniversary of the automobile, with additional standard features. The 4000S quattro was also re-named 4000CS quattro.
        --The 1987 model year was the last of the 4000s before the 80/90 series took over.

        LINK FOR COPIES OF OLD AVERTISING.... for the 4000:

        1984-87 Audi 4000 performance
        R&T March 84, 1984 4000Q, Curb Weight 2820lbs, 0-60MPH 10.2 sec, 1/4 mile ET 17.3@76MPH, 115 HP @5500 RPM.

        North American market: WIKIPEDIA

        Sales of the Quattro in North America began with the 1983 model year, which were constructed concurrently, and were of the same design as, the European 1982 models (they did not include the minor cosmetic changes of the European 1983 model) and continued through 1986. Total sales in the USA were 664. Canadian market received cars that were identical to the US cars with exception of the speedometer, which was metric like the early Euro cars. Official sales figures for Canada were 99, which included 61 in 1983, 17 in 1984, 18 in 1985 and 3 in 1986. Although it's believed that there might have been up to 6 cars bought in 1986.

        US/Canadian cars were also equipped with larger impact bumpers with built-in shock absorbers, just like the rest of the 4000/Coupé models. None of the cars came with Anti-lock Braking System (ABS), however they were otherwise "loaded" with options, including air conditioning, and in 90% of the cars, leather upholstery. Most of the 1984 and 1985 Canadian models did not have sunroofs. The remainder of the electric, suspension and cosmetic updates took place at the same time as the European cars. Out of 99 cars imported to Canada 35 are still known to be on the road.

        The initial 2.1L (2144cc, engine code "WX") engine for US/Canadian models included minor cmponent and engine control unit (ECU) changes, including lowered turbocharger boost pressure, different camshaft, emission controls including catalytic converter, and lambda stoichiometric fuel control, which lowered power to 160 hp (119 kW; 162 PS). Otherwise, mechanical specifications were identical to the European spec cars. The WX engine was also used on Swiss and Japanese market cars. In fact Audi built 200 special edition cars in 1988 with WX engine and analogue instruments, the rest of the car was identical to the MB cars of that year.

        B2 (1978-86)
        Audi 80 B2

        Also called Audi 5+5 (Aus)
        Production 1978-1986
        1,680,146 built[5]
        80: 1,405,506
        90: 105,593
        Coupé: 169,047
        Predecessor Audi 80 (B1)
        Successor Audi 80 (B3)
        Body style 2-door saloon/sedan, 4-door saloon/sedan
        front engine, front-wheel drive, or quattro permanent four-wheel drive
        Platform Volkswagen Group B2 platform
        Engine petrol engines:
        1.3 L I4;
        1.6 L I4;
        1.8 L I4;
        1.9 L/2.0 L I5;
        2.1 L/2.2 L I5;
        diesel engines:
        1.6 L TD I4

        Transmission 3-speed automatic,
        4-speed manual,
        5-speed manual
        Wheelbase 2,541 mm (100.0 in)[6]
        Length 4,383 mm (172.6 in)[6]
        Width 1,682 mm (66.2 in)[6]
        Height 1,365 mm (53.7 in)[6]
        Related Audi Coupé (B2)
        Audi Quattro
        Volkswagen Fox
        Designer: Giorgetto Giugiaro

        Audi redesigned the 80 on the B2 platform (Typ 81) in 1978 in Europe, and in 1979 (as a 1980 model) in North America. Audi continued to use the 80 nameplate in Europe, but began badging it as the 4000 in North America. The body of the B2 Audi 80 was designed by Giorgetto Giugiaro. Although it was usually ordered as a four-door, a smaller number of two-door 80s were produced. No Avant variant was available, as the Volkswagen Passat filled that role.

        In Europe, the 80 was the standard model, while after a 1984 facelift the Audi 90 was launched as a larger-engined version of the 80; with more options, and, aside from the 70 PS (51 kW; 69 bhp), four-cylinder 1.6l turbodiesel (TD) engine which was also available for the 80, two five-cylinder in-line petrol engines -- a 2.0 with 115 PS (85 kW; 113 bhp) and a 2.2 with 136 PS (100 kW; 134 bhp) which was later modified into a 2.3. The 2.2 was available with a catalytic converter and power ratings of 115 PS (85 kW; 113 bhp) for front-drive and 120 PS (88 kW; 118 bhp) for quattro models. European models had two headlamp casings, while North American models generally had quad headlamps.

        The Audi 5+5 was launched on to the Australian market in October 1981[7] and was described as a "uniquely Australian Special". After the Australian motoring press had driven the new B2 Audi 80, they beckoned Audi to fit the five-cylinder engine from the larger Audi 100. The 5+5 was essentially an 80 B2 four-door saloon with the 2,144 cc five-cylinder engine, the precursor to what would become the Audi 90.[8]
        In 1983, the 80 Sport was introduced in the UK, based on the GTE. It came with quattro-style Ronal alloys, rubber rear spoiler, deep chin spoiler, striped charcoal Recaro interior, and optional body graphics including full-length "Audi Sport" stripes. A special commemorative-edition version, the Audi 4000CS quattro, was made for the 1985, 1986, and 1987 model years.

        Mid-1984, for the 1985 model year, Audi gave the B2 a subtle facelift with tail lights resembling the ones of the Typ 44 Audi 100, and different front and rear bumpers and headlights and an updated interior. In Europe, engines with catalytic converter emissions controls were made available for the first time.

        The B2 platform proved to be both quite versatile and quite profitable; many components were shared to or borrowed from the Audi Coupé, Audi Quattro and Audi Sport Quattro, which in the process helped to cement the company into the public eye after their quattro permanent four-wheel drive system proved useful in various forms of racing.[9]
        The saloons were offered until late 1986 in Europe and 1987 abroad, and the B2-based Audi Coupé lasted through to 1988 (as an early 1989 model) before being changed. The Coupé shared many components, and its basic body shape, with the original Audi Quattro.

        4000 (1980-87)

        The North American Audi 4000 was sold in 4000S (1.8 L) and 4000CS quattro (2.2 L) derivatives,[10] with the CS quattro being very similar to the European Audi 90 quattro.

        The CS quattro had a CIS-E fuel-injected 2.2-litre inline 5-cylinder petrol engine (identification code: JT). It displaced 2,226 cc, was constructed from a grey cast iron cylinder block, with an aluminium alloy cylinder head, and used a timing belt-driven single overhead camshaft (SOHC). The rated horsepower was 86 kW (117 PS; 115 bhp) at 5,500 rpm, and the torque is 171 N·m (126 ft·lbf) at 3,000 rpm. The only transmission available on the 4000S/CS was a five-speed close-ratio manual.

        IMPORT NUMBERS: 4KS, 4KQ, COUPE, AND COUPE QUATTRO [The figures shown are exactly as they were provided by Audi of America. They are divided by calendar year, not model year.
        YEAR     4KS           4KQ             COUPE                  4 CQ        TOTALS
        1979    8,282           0                     0                             0              8,282
        1980   14,681          0                     0                            0             14,681
        1981   16,941          0                 2,553                        0              19,494
        1982   16,185          0                 4,201                     285             20,671
        1983   13,804        577               3,358                    240             17,979
        1984   19,303      3,983              3,520                      65             26,871
        1985   22,345      4,897              3,586                      73             30,901
        1986   16,436      4,174              2,846                        1             23,457
        1987   11,978      2,929              1,990                        0             16,897        
        TOTAL:123,770   16,560           22,054                   664
      • THE 4000/CGT Poor Running Checklist
        Posted by: Pre95 (1154) on 2011-12-12 22:35:36

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/tuning-cise.htm
        Edits: Removed links to images, and areas with no context.

        This file is intended to aid in the diagnostics, repair, and maintenance of cars with Bosch CIS engine management systems, and also includes a few items not directly related to this system.

        CIS: 1979 - 1983. Identified by warm up regulator attached to two fuel lines on port side of block.
        CIS-E: 1984 - 1987. Covered most intensively here.
        CIS-E3: 1987 - 1992. Similar to CIS-E, with addition of knock sensing ignition system.

        Note that if one part contributing to your engine management system is bad, it will often cause other components to function incorrectly and perhaps start to fail sooner. Your car will not perform properly if something is wrong. Waiting to fix a problem because the car still runs is taking advantage of some quality engineering in the short run to damage it in the long run.

        This file was a lot of work I didn't need to do!
        If it helped you, you should send $5 or so to me one way or another! (Link to donate to Huw is here.)

        Listed in the order of ease of checking and likelihood of failure:

        General housekeeping:
        electrical connections
        scuzz and filth reduction

        Common culprits:
        "spare" fuse
        ground at intake manifold
        idle stabiliser valve
        vacuum leaks
        control pressure actuator current, cold and warm
        control pressure actuator clogging, function
        idle and wide open throttle switches
        fuel injector seals
        oxygen sensor
        catalytic converter break up
        temperature sender for electronic control unit
        fuel pump relay
        fuel pump
        electronic control unit

        Standard tune up type items to keep on top of:
        air cleaner
        spark plugs, cap, rotor and wires
        oil and filter
        thermostat and coolant
        coil specs

        Implicated in cold/warm/hot start problems:
        injector leakage and replacement
        fuel pump check valve

        Almost never bad, look here last:
        thermo time switch
        cold start valve

        "spare" fuse

        Located in a little strip next to the rest of the fuses in your fusebox, this 10 A fuse is often mistaken for a spare and removed. Your car will run rough, if it runs at all, with this fuse removed. Cold starting will be almost impossible.

        (KE3: the fuse(s) are more likely to be clearly identified and thus less likely to be accidentally removed. Also, the 0 mA idle current of the CPR provides a reasonable "limp home" mode should power to the system be interupted)

        Ground at intake manifold

        There are two brown wires attached to a stud on the intake manifold - the connection should be clean and free from corrosion, like all electrical connections.

        Idle Stabiliser Valve:

        The ISV is used by the CIS-E (and CIS-E3) computer to regulate the idle speed of the engine, by allowing a prescribed amount of air to bypass the closed throttle. It operates when the idle switch is activated, indicating to the computer that the throttle is closed. The computer then sends a varying cycle on/off signal to this device, the percentage of time it is on versus off ("duty cycle") determining how much air it allows into the engine.

        The typical ISV problem manifests itself as an idle at the wrong rpm, and is symptomatic of the insides of the ISV being gunked up and sticking open or shut instead of doing what the computer tells it to do.

        Removing it from the car and carefully cleaning it with brake cleaner, followed by a light lube such as WD-40, will often fix this problem.

        The ISV also will not function properly if the intake manifold ground is poor, since its electrical circuit depends on them.

        Vacuum Leaks

        There are a half dozen molded rubber connectors and several sections of hose under the hood of your car, mostly connected to the intake system. These serve various purposes, including vacuum sources for brake assist and distributor advance, emissions control (positive crankcase ventilation), and idle air control. Rubber ages in the harsh environment of an engine compartment, and when it does it can crack or otherwise develop leaks. These leaks will mess up the way your engine runs, or worse yet, will have been previously "compensated" for with ill-advised adjustments, making it even harder to get your engine to run right.

        There are a handful of "sandbox" (oops, I mean shade-tree mechanic) methods for locating vacuum leaks, but this is the best thing to do:

        One fine summer day (or series of summer days), mosey on over to the auto parts store and buy several feet of the typically two sized hoses under your hood. Remove the old, frayed, worn out hose pieces ONE AT A TIME and replace them with freshly cut bits of your new hose. Do them all.

        If it is still light out (and why shouldn't it be?), you can also carefully remove the various molded rubber hose-like bits (some have three or four connections), noting how they are installed, and clean them and inspect them for damage. New ones can still be obtained from the dealer or some of the better aftermarket vendors. Do not "fix" them with duct tape, except to drive until your new parts arrive. Use new parts. Fix it right.

        If you found and repaired any significant leaks of this type, you will need to check, and perhaps adjust, your static fuel mixture - it may have been "adjusted" to compensate for the air leaks in the past.

        Control pressure actuator current, cold and warm

        The CPA current determines the fuel pressure used as a hydraulic fluid to set the fuel flow in the fuel distributor. When the engine is cold, it will typically be on the order of 50 mA. At warm idle it is supposed to be 10 mA (it will fluctuate up and down a few mA with the oxygen sensor cycle).

        (CIS-E3, with the darker grey CPA, has the advantage of idling at 0 mA, allowing a better "limp home" mode.)

        A warning: if you adjust the mixture to optimise this setting while your car is running poorly, you are probably compensating for another problem. Fixing that problem will then make the car run poorly again until you readjust the mixture. It is unlikely that the static mixture is a primary problem with a poorly running car unless you suspect it has been tampered with.

        Control pressure actuator clogging, function

        The CPA has a small electromagnet inside it that operates a valve that controls the amount of fuel that flows through it, to regulate the engine fuel supply (relative to the air sensor plate position) at the fuel distributor. I know this sounds like an unholy complication, but it is surprisingly simple and trouble free in practice. If you remove the CPA from the fuel distributor body, you will see two small fuel ports on its "working side", with little O-rings sealing them. There are tiny screens to keep it clean and if they get clogged with junk the device will not work properly. Cleaning them can't hurt much...

        If your mechanic has told you you need a new fuel distributor you might want to make sure it not just a clogged or faulty CPA, since they are cheaper and easier to replace. A known good unit from another vehicle or parts stash can be substituted to determine if this is the case.

        Idle and wide open throttle switches

        CIS-E uses two switches to enter "special" modes of operation. One of these two switches tells the computer when your foot is off the loud pedal. Under these conditions the engine is run at settings that are especially efficient, or at least very clean. At idle, the ISV is used to regulate the amount of air reaching the engine, to maintain a steady rpm. The other switch is activated during the 30% or so of widest throttle opening, and when the ECU receives this signal it abandons economy and cleanliness in favor of running the engine at a slightly rich setting. This puts the engine into a more powerful fuel/air mixture range, and also helps prevent knocking.

        (In between these points, it runs in "closed loop," reading the oxygen sensor on the fly and continuously adjusting the fuel supply to minimise emissions and maximise fuel economy.)

        To test these switches, just unplug the connector(s) going to them and use a multimeter set to "ohms" or "resistance" to measure what they are doing. When the throttle is partly open they should both read "infinite" or "out of range". This means the switch is "open." At a rest throttle position the idle switch, which is usually under the throttle body, should read "zero" ohms. When the throttle is opened most of the way the WOT switch, which is usually visible on the top of the throttle body, should read "zero" ohms.

        If either switch does not function properly, cleaning may help, but the best thing to do is replace them.

        Fuel Injector Seals

        The fuel injectors are at the end of the four or five fuel lines that go into the engine, and are pushed into the side of the head (or in some cases, the intake manofold). This "push in" fit is accomplished by the fuel injector seals, which are thick rubber o-rings halfway up the injector body. By jamming into a corresponding groove in the head they hold the injector in place and also seal the intake tract from air leaks. They get hard, deformed and even cracked with age, and are fairly easy to replace.

        Oxygen sensor

        The Oxygen Sensor is used by the Electronic Control Unit as soon as it is warm enough to fine tune the air/fuel mixture (via the control pressure actuator). On some cars (90 Quattro, 4000 Quattro), it is mounted in the front of the catalytic converter; on others it is mounted closer to the engine, in the exhaust manifold. The ones located further from immediate engine heat usually have a built in heater to get them up to operating temperature faster (the OXS has to be at something like 600 degrees to work properly).

        To check to see if the OXS is functioning, locate the connection in the engine compartment. The one shown is on a car with a heated sensor. These have two separate plugs, one for the signal and one for the heater. Cars without heated sensors (and I suppose some with them) will have the connection in other places, such as near the right side strut tower in the case of a Coupe GT. You can pull back the boot on the signal connection and expose the metal tabs. Leave it plugged in. With the engine warm, connect a multimeter set on a fairly low "volts" range (between 1 and 12) with one lead to the these tabs and the other to a good ground. You should see a steadily fluctuating voltage, that swings up and down between about 0.2 volts and 0.7 volts (200 mV - 700 mV).

        If it hangs at either end of this range, either the OXS is not working, or something else is causing a too-rich or too-lean condition beyond the systems ability to compensate. Potential culprits are vacuum leaks, a bad temperature sender, horribly uneven fuel injectors or badly leaking seals, a badly adjusted static idle mixture, or air leaking into the exhaust upstream of the OXS. In other words, almost anything...

        Catalytic converter breakup

        The catalytic converter is usually located just behind the engine compartment, as the first component of the exhaust system that is "flat" under the car. They are tin cans bigger than the exhaust pipe, with a honeycomb-like element inside composed of some weird metal (a platinum alloy?) that catalyses a pollution-reducing chemical reaction in the exhaust gas as it passes through.

        If the honeycomb physically breaks down, parts of it can come loose and get stuck in the tin can or the pipes and muffler behind it, blocking the flow of exhaust gas. This is often experienced as an inability to generate much power, or rev up the engine. The crude check for it is to rap the tin can with a hammer and see if it rattles. If it rattles, it is coming off for replacement! If not, you will want to determine other possible causes for your problems before removing it to inspect it.

        Air cleaner

        "CIS" air cleaners are a pain to change. This is because they are usually the last component before a device that measures the air flowing into the engine by having it raise a light metal plate in a calibrated cone. So the air cleaner usually ends up mounted below all the air measurement, fuel flow control and fuel distribution junk.

        The air cleaner should be replaced about every 20,000 miles, more often in harsh or dusty service.

        Spark plugs, cap, rotor and wires

        These all go bad slowly. The key to "tuning up" modern fuel injected, electronically ignited automobile engines is to remove parts that still work and replace them with new ones, ideally when the old ones are about 95% wasted. We use service intervals to help us guess when this will be.

        The cap and rotor should be replaced annually or every 15-20,000 miles, or if they show a lot of nasty black burn marks at their contacts.

        There are many expensive or trick plugs out there. It is more important to have them not be worn out or poorly gapped! Your basic spark plug, at about a dollar or so each, seems to last me about a year, or 15,000 miles. The four dollar Bosch platinums, which I really like, last a lot longer, typically up to 30-45,000 miles.

        The OEM (typically Bosch) park plug wires for these cars last a long time, but do eventually need replacment. Signs of poor wires are irregular, rough running (or "missing") when it is very humid out, visible arcing (sparks) or cracking of the rubber covers. To test wires that look ok, you measure their resistance with a multimeter set on "ohms." Your manual should be used to confirm this, but typically the spark plug wires should measure about 6,000 (6k) ohms from the cap end connector to the spark plug end connector, which is way up inside the metal boot cover. The coil to distributor cap wire should be about 2,000 (2k) ohms.

        I replace my cap and rotor every year, my plugs every other year, and wires almost never.

        Cold Start Valve

        This is an often maligned, very rarely bad part of your fuel system. It is always the first suspect in poor cold starting situations, due mostly to its name. What does it actually do? For a few seconds when you first turn the key (depending on how cold it is under the hood), fuel is sprayed through this "sixth" injector (well, we call it that in the five cylinder engine) into the intake manifold. This makes the mixture nice and rich for a moment, which helps get those first few sparks to make explosions.

        There are fairly simple test procedures outlined for them in the Bentley shop manuals, which I am not going to duplicate here. if your car is not starting well in the cold, 99% of the time it won't be the CSV itself. Once in a while the sytem that triggers it will fail to operate properly, but the problem will usually be elsewhere even in that case.

        The CSV does so little... it is an electrical injector that has constant power (12v). When the engine is cold it is grounded while cranking through the thermo time switch, and of course sprays a little extra fuel. On some cars, it is also grounded intermittently while cranking by the hot start pulse relay, adding a bit of extra fuel during warm starts.

        It can be triggered manually also.

        Electrical connections

        Folks, this is the mantra (repeat after me):

        Undo every electrical connector or connection under the hood, clean it carefully, and reassemble it using dielectric grease to protect it from moisture!

        Your engine will be easier to clean, run better in the wet, and be easier to trouble shoot when something goes bad if you are sure that at least all those little electrical signals are getting to and from the various components properly!

        Scuzz and filth reduction

        Many components of your engine and its management systems will function better and last longer if they kept clean (cam cover polisher!). The oils and vapors present under the hood, to say nothing of various road salts, dirt, acid rain, and new-cu-lar waste, are all abrasive or caustic in one way or another. Keeping their build up to a minimum will do several things for you and your engine:

        Prevent or delay disintegration of various rubber parts.
        Allow parts to heat up or cool off as they were intended to by design.
        Make it easier to see the condition of parts.
        Make it easier to see location of leaks and damage.
        Slightly minimize the grime factor when you work on it.
      • Audi Coupe VS 4000 differences.
        Posted by: Pre95 (1154) on 2011-12-12 17:38:20

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/audiwar2.htm

        This file is supposed to help people figure out what they can and can't scavenge back and forth between the two small-bodied cars Audi built from 1980 to 1987. Someday I will add a third column for the "Quattro," the third small Audi of that era.

        Front fenders, hood, grilles
        Front bumpers
        Rear bumpers, up to 1984
        Exhaust (2wd)
        Drivetrain (2wd only)
        Interior except Front seats (no tilt forward on 4000), Center console is wider on quattro
        Wiring harnesses except 1985-on power window harness
        (front) Door handles
        Tires and wheels by year except 4000 Q is 4 x 108 like all 1985-on cars

        All Glass
        Rear bumpers 1985-on
        Outside rear view mirrors
        quattro exhaust
    • - Performance & OEM Vendors -
      Posted by: Pre95 (1154) on 2011-12-12 17:00:55

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    • - Body, Trim & Lighting -
      Posted by: Pre95 (1154) on 2011-12-12 16:59:51

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      • Door & trunk seals
        Posted by: blewtoon (989) on 2018-03-06 23:11:33

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      • Cupra R lip installed on B2 facelift bumper
        Posted by: alxdgr8 (6515) on 2016-05-26 19:34:18

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      • Relaying the parking/interior light circuits
        Posted by: pinkmanct (7384) on 2015-02-20 02:21:57

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        --Remove the top from the instrument cluster.
        --Run a fused 12G red wire from the battery to the back of the instrument cluster.
        --Snip yer wires and install the relay.
        --Wrap the relay with a bit of foam and tuck behind the cluster.
        --Check your work
        --Reinstall cover.

        You are done.

      • sunroof seal restoration
        Posted by: blewtoon (989) on 2012-03-23 14:55:24

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      • Trunk Leaks
        Posted by: Pre95 (1154) on 2011-12-15 02:00:17

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/trunkleaks.htm

        A lot, sometimes. What a pain! All I can think of, besides my 1962 Harmony hollow body suffering the ignominy of the dampness, is my floor pan slowly rusting out!

        Apparently there are at least four reasons for this problem.

        One, the original spoiler on my car, which was attached solidly all the way across the trunk and irritating me by acting as a dam for snow and rain, was also causing rust and leakage at its mounting bolts. Ironically I finally realised this as a used later model style spoiler, which only attaches at the ends, was on its way to me. The later model spoiler bolts are outside the trunk sealing gasket, so even if they leak they don't let water into the trunk. The old spoiler came off with a big hammer, two pry bars and some scraping. Then I had to do a LOT of scraping and sanding to get rid of the old goo that sealed it down, and the surface rust it had created. I bit fiberglass window screen and Bondo filled the old holes, a quick coat of paint (pink! - the closest I had to gold...), and I mounted the new spoiler (using new plates under the lid from the dealer).

        Two, the tail light assemblies are almost certainly leaking at their gaskets. The fix is to remove them, clean up the old gasket material, and remount them using either black RTV or some of the "3M Strip Calk" (#051135-08578 - auto parts stores) that I keep around for lots of speaker and car related projects. I am leaning towards the Strip Calk, it is very good for some things - like my rear logo which I attached after the above project using nothing but some of this stuff, to the center of the trunk lid, and it's still there 6 months later! It's main advantage is it is a lot easier to remove than RTV if I have to replace a lens or do some bodywork.

        Three, I have been informed that the mounting bolts for the bumper side molding (four on each side) probably leak by now. I agree. So someday they have to come off and either get new factory gaskets, or the Strip Calk treatment.

        Four, a recent north easter (I park my car facing roughly south west...) managed to fill the stupid trunk lid with water! Which then ran into the trunk when I opened the lid! So I guess the mounting bolts for the rear trim - the black on each side of the license plate and the big red reflector/"coupe" logo thing, also leak.

        So let's see, stock, my car had at least 40 bolt holes leading into the trunk which could eventually leak water, and the taillight lens gaskets.

        And then there's the holes rusted in the rocker panels...
      • Convert Corner lights into Parking and Turn Signals
        Posted by: Pre95 (1154) on 2011-12-15 01:40:32

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/parkturn.htm
        Images: Originally from Huw's Audi Garage

        For a long time, I did not like that cars to my side could not tell if I was signalling. A couple of years ago I took a pair of parts bin side marker lights, the little orange ones about 1 x 2 inches, and mounted them in the ends of the bumper and used some bits and pieces of spare harnesses to splice them into the turn signal circuit. I had to modify the back of the lenses a bit, to make them fit a simple round hole. Then I used a bit of hot melt adhesive (industrial grade stuff I use on my speaker work) to make sure they would stay put..

        Now I have installed the 85-87 corner marker lights with my round headlights and a relay to make them flash along with the signals. This solution is applicable to all the type 85 cars from those years. I have wired the relays so they are switched by the difference between the parking light circuit and the turn signal circuit, which is easy because they are both grounds when "off."

        It is also necessary to load the flasher unit with a light bulb filament in order for it to flash at the correct rate, so I used a couple of parts bin (ex-87 5000?) sockets that would fit the original bumper lens and house dual filament bulbs. This way the bumper light is also a park and signal device. Without doing this you would have to wire them as signals an give up their parking light function, which is not too bad since you will still have the corner markers anyway.

        You might ask, why not just substitute a dual filament socket in the corner lens? I tried to find one and nothing in my parts bin came close enough. The socket is different than the bumper one, in that it has a different depth of protrusion into the lens itself.

        So to make this work you drive the corner bulbs as shown in this diagram, and make sure there is still a filament loading the front turn signal wire, one way or another.

        Here is the circuit diagram for changing your Audi coupe/4000 (and many others) corner marker lamps to dual-duty signal and marker lights:

      • Tail Light Grounding
        Posted by: Pre95 (1154) on 2011-12-12 17:24:39

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/taillights.htm

        A common trait among older Audis (funny to watch, a pain to suffer) is the "Christmas Tree" tail light syndrome. The symptoms are random seeming functions of the various lights in the rear clusters. You signal left, and both brake lights flash as well as the left signal. At a much diminished brightness. You turn on the lights and the whole darn cluster glows dimly.

        This is caused by the "minimalist" approach Audi seems to have taken with some of their wiring specifications. The entire tail light system, both sides, is grounded through one small brown wire. Eventually this wire ages, perhaps corrodes a bit, it's connections become poorer, and it just won't handle the current required any more. Due to another interesting feature of much Audi wiring, that devices when "off" frequently have their hot side grounded, the voltage present at the desired lamp takes another path of lesser resistance: through the other lamp(s) "backwards" to their grounded hot side.

        This may seem odd, if you think of the tail light assembly as being "grounded", but it isn't any more. It has a crummy old wire presenting 10 or 20 or 50 ohms to ground. So the active lamp and the brown wire (it's more of a resistor now) act as a voltage divider and the whole ground portion of the tail light cluster(s) sits at some voltage between 0 and 12.

        The solution is to add a pair of adequate grounds to the clusters. These assemblies are like giant scale PC boards. There are metal traces running all over a big piece of plastic, leading from the terminal strip to the various lamps. You first remove the wiring harness from them, usually by squeezing a couple of snap locks on each side. (At least these don't seem to break, but I wouldn't do it below 50 degrees F anyway) Then you remove the "circuit board", again usually by squeezing a couple of big tabs to release it into the trunk area.

        Identify the ground track. On my 5k I had to drill a hole through the ground track and attach a ring terminal to a bolt through this hole. On the coupe there is a convenient 1/4" male tab on each one - as if they knew this needed to be done! You lead a short 14 or 16 GA wire from here to a nearby location on the trunk metal. Try to pick somewhere that stays dry and will keep your new wire safe from physical abuse. Use an existing bolt to hold a ring terminal if you can, if you must, drill a small hole and use a small sheet metal screw to hold it. Work neatly, solder the wire to your terminals, and use heat shrink tubing to keep them clean. Use dielectric gel on the contact points.
    • - Steering System -
      Posted by: Pre95 (1154) on 2011-12-12 16:59:18

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      • Tie Rod End Replacement
        Posted by: AudiCoupeGT (11459) on 2014-03-25 00:07:07

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        In a recent post of mine, I showed a picture of my outer tie rod ends. Both the DS and PS boots were completely collapsed and the grease had long disappeared.

        I decided to go ahead and try and replace them myself. Before diving into this, I watched a few videos, checked what tools I would need, and got my Bentley ready. The job seemed pretty cut and dry but it never hurts to put up a DIY for the newer DIYer. This job is fairly simple but take the necessary safety precautions and do so at your own risk. YMMV

        Tools required:
        Jack & Jack Stands
        Metric Wrenches and sockets (17 and 22mm)
        Some good penetrant (I used Liquid Wrench)
        New Tie Rod Ends
        Hammer (Brass/Rubber)
        Torque Wrench
        Rags/Shop Towels

        Optional Tools:
        Anti-seize Compound
        Breaker Bar
        Tie Rod Puller Tool

        1) Park the car on flat level ground (if possible) and engage the parking brake. Jack the car up till the front wheels are off the ground and use Jack Stands. Don't trust the Jack to hold the car up and be stable at the same time while you are trying to bust open rusty bolts. I would recommend putting some wheel chocks on your rear wheels as well.

        2) One the car is up on Jack Stands and you have insured it is safe to be underneath it, remove the front wheels to expose the tie rod.

        3) Spray some good penetrant on the self-locking nut on the top as well as the sleeve locking nut on the back of the tie rod end. Allow the penetrant to really soak for a good few minutes. (I sprayed a crap load on and waited till the next day)

        4) When you feel like you've waited long enough, grab your breaker bar, a 17mm socket and a 22mm wrench. the 17mm socket/wrench will be used for the self-locking nut on the top of the tie rod end. The 22mm wrench will be used for the sleeve nut. Crack loose the 17mm self-locking nut and loosen the sleeve with the 22mm wrench. In my pictures, the 22mm wrench will be on the nut that has the yellow arrow pointing to it. Keep in mind, the sleeve nut actually has to be "tightened" to pull off the tie rod end.

        5) When both nuts are loosened off, you can remove the tie rod end from the steering knuckle. Give a swift blow to the top part of the tie rod end with a brass hammer/rubber mallet should pop it out of the knuckle. If yours has not been touched in a long time or you happen to live in the rust belt, it's best to get a tool which makes this job fairly painless. I picked up a tool similar to this for about $20 and it worked well. Keep in mind, there are similar tools and methods that will work just as well so it comes down to personal preference. End result pics included.

        6) Now that the tie rod is free from the knuckle, we can put the new tie rod end on! Before you remove the tie rod end, STOP! There are two ways I know of removal. First, is to take a paint marker or something similar and mark where the end of the tie rod end sits on the tie rod. Alternatively, you can count the number of turns it takes to remove the tie rod end. The reason for these methods is to ensure that when we install the new ends, we keep the alignment similar to before.

        7) This is a good chance to clean up the area. Make sure the threads are clean on the tie rod. I would recommend using some anti-seize compound on the threads of the tie rod and the tie rod end at this point. Reinstall the new ends to the mark that you left before removal or count the number of turns.

        8) Next, push the tie rod end back up into the knuckle and use your new self-locking nut to tighten it on. The top self locking nut can then be torqued on to the appropriate tightness. According to the Bentley manual, this is 30Nm (22 ft lb). The Sleeve nut can also be tightened now. The torque spec for this is 40Nm (29 ft lb). Double check that you have tightened everything to spec and that there is no longer any play in the rod ends.

        9) Marvel at your work!

        10) Re-install wheels and bring car back to the ground.

        At this point, I would go for a quick run around the neighbourhood to make sure everything feels alright. It's highly recommended that you should get an alignment done shortly after doing this job.

        This is was my first attempt at a DIY so any suggestions/tips or additional info is welcome.
      • Steering Rack Replacement
        Posted by: Pre95 (1154) on 2011-12-12 17:18:47

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        Original: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/rack.htm

        (This is specifically written for the type 85 - Coupe GT or 4000 models - but with not much adaptation should work well for the type 89 - 80 or 90 models - as well.)


        new/rebuilt rack
        two liters of 7.1 mineral fluid (correct me if I'm wrong) one to flush, one to fill, basically.
        perhaps a new little S-shaped metal pressure line while you're in there
        new PS reservoir filter
        a few new locknuts - for the tie rod/rack bolts, for the rack mounting, and I think for the column bolt
        new rubber gasket for the steering column hole in the firewall

        doing the job (it is highly unpleasant, by the way!)

        A lift helps a *lot* but the job can be done without one. You at least need the front tires off the ground.

        undo everything...

        the nuts and bolts that go thru the tie rods
        the bolts that hold the tie rod bracket to the rack
        the two really hard to get to and turn nuts that hold the rack to the firewall
        the two bolts in the wheel well that hold the end of the rack
        the bolt that locks the splined steering wheel shaft to the pinion shaft
        and probably the two bolts halfway up the steering column that hold it together, for manouevering room - there is a metal plate that is bent against these nuts to prevent them coming loose, just pry it down flat to get them out.
        the pressure and return hydraulic lines at the rack - be prepared to catch the fluid!

        Turn wheel all the way to the left (I think) to make the rack as short as possible.

        Now you must separate the pinion shaft from the steering column lower half. This is tough - as I recall it took me a long time and a lot of efforts with various special big hammers and pullers. At this point you are basically pulling the column up away from the rack.

        Wrestle the rack out of the car. This is an exercise in four dimensional geometry and advanced Buddhism, by the way. Try to remember how you twisted, turned and moved it along the way so the new one can be Rubiked back into place.

        Time for break one...

        This is when I played at flushing fluid a bit. The return line will have dumped all its fluid, I think, so I added some fresh to the reservoir and cranked the engine with coil wire to run the pump, for brief intervals, until the stuff that came squirting out of the pressure line was nice and clean looking. I probably removed the old filter (in the reservoir) prior to this and installed the new one afterwards. Just be sure not to run the pump dry, by keeping the fluid level up in the reservoir.

        Break one is over, go back to work.

        Remove the old firewall seal and install the new one - it has a plastic frame around the rubber part.

        Run the video of rack removal backwards and duplicate all your gymnastic procedures to get the new rack roughly into place against the firewall. Make sure all seems happily located, and replace all the nuts and bolts you undid earlier using new locknuts. Leave the steering column to pinion shaft assembly for later - you'll want to make sure the rack is centered at the same time as the steering wheel I think.

        Now, hook up the hydraulic lines, carefully. I think I did another flush phase here, or at least used the pump to fill up the rack till it spewed clean fluid.

        Center the rack, basically by returning the wheels to the straight ahead position - can be done gently from the tires, since the wheel isn't hooked up yet. If you can manage it, get the lower steering column back on so the wheel is straight as well all at the same time. If it isn't, you can always pull the wheel and recenter it - which might be easier, come to think of it.

        Replace and tighten the column to pinion shaft bolt and new locknut and the two bolts holding the column together, rebending the safety metal piece that jam the nuts from undoing.

        I suspect at this point everything is reassembled and "fluid tight." Good time to take break number two, while casually but carefully checking every nut and bolt you've touched to make sure it's been reinstalled and torqued properly. End of break number two...

        Fill the PS fluid reservoir to the "full" mark and crank the engine (coil off still) a few times to get fluid through the lines and rack etc. as much as possible. When you're satisfied that the level is holding pretty steady, reconnect the electrics so the engine will run, and wiht it running slowly turn the wheel from lock to lock a few times to finish filling/purging the PS fluid. Keep an eye on the reservoir level while doing this. Pay attention carefully for unpleasant noises or inconvenient leaks.

        Clean everything up carefully, recheck all your nuts and bolts, and lower the car onto the ground. Take a short, careful test drive to make sure everything works, the wheel is centered, and then check again for leaks.

        Take break number three by putting your tools away. If alcoholic beverages are mandated as part of your car repair tradition, please do not perform any more test drives or mechanical work today.

        Finally, experience the nervousness which hopefully transforms to exuberance as you drive the car over the next few days and the wheels don't fall off, it goes where you point it, etc.
    • - Fuel / Air Delivery Specific -
      Posted by: Pre95 (1154) on 2011-12-12 16:59:00

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      • Control vs. System Pressure in CIS systems.
        Posted by: 87SpecialBuild (4420) on 2013-05-06 01:03:45

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        When it is time to check pressures and control current. Pressure needs to be checked with the fuel pump running. System pressure can be checked at the line out to the cold start valve-- you can look it up but I believe it should be around 90 psi. Differential pressure, checked at the test port on the bottom half of the fuel distributor, should be about 7.5 psi less than whatever system pressure is--with the EHA unplugged.
        Control current to the EHA should be about 25ma key on and should jump to 50 ma or higher when cranking, based on engine temp. The colder the coolant sensor, the higher the ma output during cranking and warmup. Increasing current to the EHA should cause diff pressure to drop. In other words, system pressure should never change but diff pressure should get lower than the 7.5 PSI drop as current increases. It is a two way street, reversing polarity will increase diff pressure, that is how it does decel fuel cut. If diff pressure equals system pressure no fuel will flow to the injectors.
      • Fuel tank repair (pics to follow)
        Posted by: Tony Hoffman (1624) on 2012-12-18 08:32:41

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        Before you start reading this, keep in mind any articles written by me are "for reference only". I am not an expert, and if you wish to contribute, please let me know. I do, however, have a fair amount of experience with Audi's. This began with my first when I was 15. It was a 1976 Fox, and I knew very little about cars. Since then I have owned several other Audi's, and hope to pass on some knowledge I have learned.
        So, here we go.

        This article covers how to repair a fuel tank. Specifically, the tank being repaired is out of a 1987 Audi 4000 CS Quattro. This car has an external fuel pump, a pre-filter for the pump, and a fabric-type screen in the tank. This is in addition to the regular fuel filter after the pump. The in tank screen type filter gets plugged up over the years with rust and junk from inside your tank.

        First off, how did I diagnose this problem? Well, the car would only run for about 20 minutes or so, and the fuel pump was extremely noisy. When I pulled the feed line off the pump, gasoline hardly came out at all. Then I pulled the hose off upline from the pre-filter. The fuel still wouldn't come out like it should. This was with a full tank of gas-of course! When I pulled the return line, gas poured out of it like it should have been coming out of the feed line. I should mention that the return line has a rubber hose on the end of it to prevent this, but it gets hard over time. However, if fuel doesn't come out of your tank, this is why.

        The 4000's use a basic rectangular tank, with a small extra chamber in the bottom. This is blocked off except one small oval hole. This is done to ensure the car doesn't cut out during hard cornering.

        First thing to do is drain and remove the tank from the car. Then clean the tank properly.


        There are three ways I know of to ensure the tank doesn't explode. The first is "old school". That is to burn the tank(dangerous, but effective). The second is to wash it out very well. The last is what I do, fill the tank with soapy water.

        You can use dish soap and water and "swoosh" it around a bit in the tank. After doing this two times, I filled the tank with soapy water again in preparation of cutting the top off it. This way, there are no fumes left in the tank to explode. This is very important. If there are fumes left in the tank, it will explode with the first spark or open flame around it. I say this from experience, I've burned my hair and other things plenty in the past 15 years!

        The next step can be done on of several ways. It is cutting the hole in the top of the tank. I felt the easiest way was with a metal cutting blade on the skilsaw. However, you could use a cutting torch, angle grinder, dremmel, plasma cutter, or drill and sawzall. You can also choose where to cut your hole. I did it in the top of the tank for several reasons. It has a lesser chance of leaking, with no pressure from the weight. It also gave me plenty of room to cut a hole big enough to work with.

        Then, you will need to cut the lower level open. I did this with the dremmel, since I couldn't fit the skilsaw into the hole I had cut. I cut toward the back of the tank, and then made two cuts to the side over the drain tubes. This allowed me to bend the top of the chamber up to access the feed line and filter.

        I took the dremmel, and cut off the filter end. It is spot welded to the bottom of the tank about one inch from the filter end. I bent it back and forth till it broke loose, and took it out. If you wanted, you could just cut about an inch out of the tube, and leave the filter in there.

        Now the Filter is cut off:

        Here is a pic of the filter:

        Next, I decided to take my tank to the power washer and clean the inside the best I could. This is up to you, but I didn't want to plug the new pre-filter right away.

        Then, you have the option of coating the inside of the tank. I've done this several times, with excellent results. You have several products to choose from. I have used "Kreem" in the past, and because it comes as a three part kit with everything included, it is my personal choice. You will have to acid etch the tank. Then, let it dry completely. This will be a two step process in this application. First, you will coat the bottom chamber. Then the main part of the tank once the plate is put back into the hole you made. You will need to read the directions on the bottle and follow them. I'd recommend doing the bottom of the lower chamber first, the bend the tab back down after it dries and seal the top of the bottom chamber.

        If you are not going to seal the tank, I'd recommend you seal the sides of the lower chamber where you cut. I did this with "seal-all". This will ensure you keep the baffling in place for hard cornering.

        Then put the top piece back on the top, and weld or epoxy it in place. As you can see, I've welded a piece of metal to the top for a handle. This we found to be unnecessary, as the piece held itself in place. Then, coat the outside with a good sealer (once again I used Seal-All). Next, you will finish coating the inside by doing the main part of the tank. This will also ensure you have sealed the part you cut out of the tank, if you are worried about that.

        Once it is dried, you can re-install it in your car.

        I'd recommend replacing the lines and filters at the same time. The pre-filter is NLA, but Autozone has a filter that works well. I've used it on several cars. Part # FF3-8DL.

      • Idle Stabiliser Valve (ISV)
        Posted by: Pre95 (1154) on 2011-12-15 01:47:09

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/isv.htm
        Images: Originally from Huw's Audi Garage

        ISV stands for Idle Stabiliser Valve. What it does is, um, stabilise the idle speed of the engine. Present on all CIS-E vehicles, it is controlled by the fuel/air ECU, in response to the temperature sender in the upper radiator hose flange, the engine speed information from the coil/tach signal, and the idle switch on the throttle body.

        The ISV is placed in such a way that it acts as a valve between two hoses, one of which is connected ahead of the throttle body and one after it. Thus it can allow air to bypass the throttle butterflies to maintain an appropriate engine speed. Normally, the ISV is partially open. When it is called upon to function, the ECU sends it a pulsed signal which rapidly opens and closes it. This is measured as a duty cycle, or percentage of time it is open.

        When the engine is warm, not much air is required to keep the engine running and the ISV is supposed to have a duty cycle of 27%, which is just about at the minimum possible (the ECU only runs down to 25%). When the engine is cold it takes more air (and more fuel, also controlled by the ECU) to keep it idling, and the ISV is run at a higher duty cycle to manage this. This is one of the advantages in terms of economy of CIS-E over the older more mechanical CIS. The older system manages the enrichment and air increase via two internally heated devices whereas CIS-E uses direct measurements of engine parameters and adjusts accordingly.

        The most common "failure" mode exhibited by the ISV is to get clogged up with slowly accumulating oil and gunk (which is drawn into the intake tract by the PCV system) to the point where it will not respond properly to the ECU control. Since it is often a matter of "getting it going," this will occur at the most inconvenient time, that is when the engine is cold and the ISV has had time to get stuck in its congealed state. So if you have to depress the accelerator to keep the engine running when cold, or if your idle is erratic and unstable, fixing the ISV is a good place to start troubleshooting. (A tune up couldn't hurt either! How old are those plugs?)

        To fix the ISV, you clean it. Undo the hose clamps, unplug the wire connector, and wrestle it free of its mooring devices. Bring it somewhere well lit and reasonably well ventilated and use a bunch of brake cleaner to wash it out. It does not hurt and might just help a little to apply 12 volts to its terminals intermittently, activating its little solenoid and causing it to flutter open and shut. This will help get all the gunk out of its nooks and crannies.

        Reinstall it carefully, making sure the electrical contacts are clean and protected from future corrosion with a little silicon dielectric grease, and see if it helps!

        This is what a typical ISV looks like:
        (except they are usually rather corroded, and nasty with oil and dirt)

        This is where it goes, on some cars anyway:
      • Air Filter Replacement
        Posted by: Pre95 (1154) on 2011-12-14 12:39:12

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/airfilter.htm

        It's a certainty that on every vehicle, there will be some routine maintenance job that is almost impossible to do. For example, there are V-8's where one spark plug requires removing the exhaust manifold to change it. On our CIS vehicles, one such item is the air cleaner. This is due to the fact that the fuel flow to the engine is regulated by an air sensor plate hanging in a cone shaped passage, which is raised by the flow of air to the engine. So the first thing the air has to do after being filtered is flow upwards, through the fuel control system.

        Of course, since there isn't much room elsewhere under the hood of an inline 5 cylinder car, that tends to put the air filter directly under the fuel distributor!

        There are two schools of thought when it comes to changing these air filters, although one can be translated into a dirtier version.

        One, and probably generally the easiest, is to remove the headlight in front of the air box. Now, when the clips are undone (with the help of a coat hanger), and the top of the airbox is lifted an inch or two, the air filter can be fished out and removed through the opening in the front of the car.

        The other method is to dismantle enough on top of the air filter box to enable you to lift it up and out. This can get pretty scary! Let me say now, that with the A/C removed from my car, I can coax the top of the airbox just high and crooked enough, to wrangle the filter out and put a new one in without disconnecting anything. With the A/C parts still in place this would not work.

        So how do you do it this way? You remove the thing they call the "boot", which is the very attractive black molded rubbery thing that connects to the top of the air box and to the inlet if the throttle body. Each of these attachment points is just a matter of loosening a big hose clamp (hopefully the last dismantler or the factory put the screwheads where you can reach them. remember this when reassembling!). There will be one or two hoses or devices attached to the sides of this "boot" - and unfortunately there always seems to be one attached to the bottom of it. This one is nasty. While it isn't too hard to remove (loosen hose clamp, pull off), replacing it is a pain. You have to somehow press it into place with the boot just about returned to it's home, thus in your way, and tighten the hose clamp gracefully, maintaining a good seal.

        With the boot removed, it is now a lot easier to lift the fuel distribution mechanisms up high enough to clear the air filter and remove it. You may have to disconnect one or two electrical connections, so remember where they go. Don't force anything - move slowly and keep looking at how you are pushing things around. The fuel lines themselves are quite flexible, but you still don't want to bend them more than necessary. If you're unsure at all about remembering where all these connections go, take some simple notes as you go, perhaps marking them with bits of tape or bread wrapper tags.

        When closing everything up, make sure the air filter is seated properly - it's easy amidst all this pushing and shoving to leave it's gasket-like edge up a little and catch it between the halves of the air box. Make sure you reconnect every vacuum line and electrical connection that you undid. Be sure to tighten hose clamps in such a fashion as to make them easiest to get to next time, and try not to leave any tools or "leftover" hardware inside the air tract or engine compartment.

        I hate finding that missing screwdriver two weeks later when I pop the hood to check my oil....
      • Replacing Fuel Injectors
        Posted by: Pre95 (1154) on 2011-12-12 17:22:49

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/injectors.htm

        This file is supposed to help you change your injectors - I suppose it is also a handy reference for simply changing seals as well.

        This file provided by: Huw Powell, on or about 2/8/2000.

        Start with a set of new injectors and seals.

        There are also plastic inserts screwed into the head (intake manifold on the 87.5 Coupe GT) that the injector with its seal(s) pops into, and these have their own little seal at their base. The injectors shown in my picture are the early, unshrouded type. The later style have little metal hats on the tips, where a second, smaller seal is located. I had already replaced my plastic seats, and the seals on my old injectors are fairly new. You're supposed to try to get the green "Viton" seals cause they last longer, especially for the tip seal in turbocharged applications.

        The ends of the fuel lines on my car were 12 mm and the injectors 14mm. It is a good idea to use hydraulic fiting wrenches here - they grip four of the six faces of the hex and are supposed to cause less damage to the (unreplaceable!) faces.

        There is a $20 VW tool available that gets a nice grip on the them so you can pry with a screwdriver and have your force go in the right direction.

        A small dentists pick tool can be useful for removing recalcitrant seals.

        To prepare to do this work a few precautions need to be taken. You are working on the fuel system of the vehicle, and gasoline is a very dangerous substance. Ideally you should work outside. You should at least have very good ventilation. Wear goggles! Do not smoke!

        I did two things to make this job easier. One was to remove the Idle Stabiliser Valve, which sits right over the number five injector on CIS-E cars, pretty much blocking access to it, and the other was to remove the remaining fuel pressure in the lines by powering the Cold Start Valve manually. The first item is fairly generic - anything in the way of your injectors, you might want to remove to make the work easier.

        Releasing the residual fuel line pressure is handy because the injection system will usually have an ounce or two of fuel at about 50 psi stored in the lines and fuel distributor. This will come spraying out in the worst directions when you open up the first injector fitting if you do not bleed it off. I had the crack pot idea of using the Cold Start Valve to do this. The CSV is the sixth injector like thing, bolted to the intake manifold with an electrical connection going to it. Remove the electrical connector, and simply power up the CSV with a couple of jumper wires (polarity doesn't even matter, it is a simple solenoid) and dump the fuel into the intake manifold! I left the wire off until I was done, because it was one more item that crosses in the way of the injectors.

        Now we are ready to actually start working. If your car has an injector retaining rail, remove it first. Mine was bolted in with two Allen head bolts, the front one was easy to get to, the rear one was a bit tougher.

        I started at the front so that the job would get progressively more difficult as I worked.

        All you have to do to remove an injector is pull it out of the head (or manifold). This is quite easy if the seals are in good shape - I pulled the first three out completely by hand, pulling gently on the fuel line exactly along the axis of the injector. I used the tool on numbers four and five due to lack of room for my hand.

        It is recommended to use the injector removal tool for all the injectors, especially if you have not worked on this assembly before. The tool grabs the injector/fuel line joint at a place where force can be applied without damaging anything. Yanking on the fuel line when the seals have fossilised may result in broken fuel line ends, and cost you a lot more in time, money, and aggravation.

        Put the short leg of the tool under the injectors protruding end, catching the skinny part in the tool. Then use a screwdriver to engage one of the slots in the long leg of the tool, and use the cam cover as a fulcrum to apply pressure to the tool. It will pull in the correct direction, exactly in line with the axis of the fuel injector and if you are lucky it will pop right out, with the seal still on it. Wrestle the injector and its line up out of the cave in which it lives into the light where you can get tools at it.

        If the seal stays stuck in the seat, use a pick to get it out.

        If you are replacing the seats as well (you should), now is the time to carefully remove the old seats and their little gaskets, clean the area nicely, and install the new ones.

        Now with the old injector still attached to the line, but laid out on top of the cam cover, prepare the new injector for installation. take off the nifty plastic caps. Lubricate the new seal(s) with gasoline and slide/roll them onto the new injector. Bring this prepared injector over to the car and place it on a clean rag within reach of the fuel lines.

        Remove the old seal from the old injector if it is still there. Using your hydraulic fitting wrenches, loosen the old injector. One of my pictures shows this being done hidden under a rag, over a small container, just in case there was still residual fuel pressure in the line. There wasn't.

        Now undo the old injector by hand until it comes out of the female fitting. I tried to move quickly and carefully at this point to avoid getting any crud into the center area of the female fitting, where it would get forced intot he new injectors. Grab the conveniently placed, properly prepared new injector and seal(s), and screw it into the fuel line fitting till it is snug.

        Then raise the fuel line a little to make sure there is no strain on the fitting, and using the two wrenches tighten the injector into the fitting. (I had to use a regular 14mm on the injector because the new seal was in the way of sliding the hydraulic fitting wrench on. Oh well.) The torque is pretty light, about 18 foot pounds I think.

        Wrestle the fuel line and new injector back into the grimy cave in which they live, trying not to get any of that grime on the new seal(s) or on the new injector. Position them over the seat and push gently. The injector and seal should pop with moderate ease into the plastic seat.

        Assemble / Test:
        When you have fought your way through doing the fifth, and most difficult, injector, you are ready to start reassembling. Reinstall the injector retaining rail if there was one. Replace any hoses or components you removed in order to gain access.

        Clean as you go! Wipe off dirt and grime if you can. Electrical connections should always be improved with contact cleaner and sealed with silicone dielectric grease when you have the opportunity.

        Make sure everything is in its proper place, and that there are no stray tools in the engine compartment. If you are indoors, open all the doors even if it is cold out. My suggestion would be to crank the car for a moment - whether it catches or not, turn it off immediately and have a good sniff around the engine compartment for gasoline leaks. If there are none, start it again (it may take a moment as all the fuel pressure was bled off) and if it is inside, drive it outside. With the car running (and the exhaust not pointing into the house!) check again in the engine bay for fuel leaks and any other bad things.

        Test drive.

        Put the old injectors in a plastic bag, mark it, and keep it. Someday they will be worth a small fortune, and you will be able to retire to an island in the South Pacific because you saved them.

        If you have any gasoline soaked or stained rags dispose of them properly! Do not place them in a trash container indoors as they can spontaneously combust and you might die. They should be kept in an open, metal container outside, until they can be turned over to the Federal Oil Rag Department for proper disposal.

        I was very pleased with the results of this job. My engine drives smoother at any given RPM, and the power band is also smoother as the car accelerates. I don't know if I will see any effect on fuel economy, it is certainly possible. The middle of a New England winter is a difficult time to observe the fuel economy effects of car repairs unless they are drastic.
    • - Emission System Specific / Smog -
      Posted by: Pre95 (1154) on 2011-12-12 16:58:16

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    • - Electrical & Vacuum -
      Posted by: Pre95 (1154) on 2011-12-12 16:57:46

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      • CIS-E Vacuum system (84-87)
        Posted by: Pre95 (1154) on 2011-12-15 02:18:34

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/vacuum-system-E.htm
        Images: Originally from Huw's Audi Garage

        This is how the various components of the 1984-87 Coupe and 4000 vacuum systems are connected. Line thickness represents approximate hose type. The thickest are molded rubber or plastic. The connection to the throttle body is ahead of the butterflies.

        Color codes:
        red = brake power assist system
        yellow = emissions systems - PCV and fuel tank vapor recovery
        blue = idle management
        green = fuel injector "air shrouding" system
        orange = distributor advance
        purple = AC only systems

        Explanation of functions: (color coded)

        Power brakes - I dunno how it works but it seems to be set up to grab vacuum wherever and whenever there is any available.

        Emissions systems (YELLOW) - draws crankcase fumes into the intake air ahead of the sensor plate under load, at idle (closed throttle) it cheats and draws it, without letting the sensor know, into the intake manifold. There is also the fuel tank vent system, coupled with the charcoal canister. I'm still trying to figure out which direction the air flows in some of these hoses, and when...

        The idle, warm or cold, is adjusted by the computer using the idle stabilizer valve, whenever the idle switch on the throttle body is closed. It works by rapidly opening and closing as needed, from its rest position which is partly open.

        The fuel injector "air shrouding" system is, I think, designed to help cool the injectors to reduce the problem of vapor lock (this occurs when too much heat soaks into the injectors, after a hot shut down, and causes some fuel to turn to vapor, which prevents the fule system from applying proper pressure to the injectors in order to open them). I believe this system simply draws a small amount of air that has reached the intake manifold back through the throttle body, forcing it to travel via some carefully designed cavities around the injector body (between the tip and main seals).

        The distributor advance is pretty simple (!), advance is determined by the pressure drop relative to atmospheric just ahead of the throttle body butterflies. This seems to be at its greatest when the throttle is just opened a little bit.

        In the middle of this hose there is a little vacuum actuated switch with a screwdriver adjustable center (not shown). I always thought this was some mysteriously important bit of gear. Now I know it's just a sender for the upshift light control unit.

        The AC line shown is used to store vacuum, through a one way valve, in a canister (three tennis balls) under the left fender, and when the heater control is moved all the way to the "cold" position an electrical valve uses this vacuum to close the recirculating flap.

        I have not shown the vacuum supply for the differential locks on the quattro models, but it is similar in location and function to the recirculation flap system, although I do not think it has a storage system since it only functions when the car is in motion.
      • CIS Vacuum System (Early, to 83)
        Posted by: Pre95 (1154) on 2011-12-15 02:10:02

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/vacuum-system.htm
        Images: Originally from Huw's Audi Garage

        This is how the various components of the 1982 Coupe vacuum system are connected. Line thickness represents approximate hose type. The thickest are molded rubber or plastic. The intake manifold numbers indicate the connections from the throttle body forward, they are out of order for simplicity (?) in the diagram. The connections to the throttle body are both ahead of the butterflies. The AC components referenced have been deleted from my car.

        Color codes:
        red = brake power assist system
        yellow = emissions systems - PCV and fuel tank vapor recovery
        blue = cold idle increase
        green = cold engine acceleration enrichment system
        orange = distributor advance
        purple = AC only systems

        Explanation of functions: (color coded)

        Power brakes - I dunno how it works but it seems to be set up to grab vacuum wherever and whenever there is any available.

        Emissions systems (YELLOW) - draws crankcase fumes into the intake air ahead of the sensor plate under load, at idle (closed throttle) it cheats and draws it, without letting the sensor know, into the intake manifold. There is also the fuel tank vent system, coupled with the charcoal canister. I'm still trying to figure out which direction the air flows in some of these hoses, and when...

        The cold idle increase operates by allowing extra air to bypass the throttle body until the auxiliary air valve is closed. The aux air valve is powered by the same circuit as the control pressure regulator and the fuel pump, so it is always on, I presume it has a heater which causes it to close, gradually, after a preset interval.

        The cold engine acceleration enrichment system is complicated. There is a pressure differential diaphragm inside the control pressure regulator which also alters the control pressure (the main control is the bimetal strip). The two vacuum lines are connected to each side of this diaphragm. Under low load conditions both sides are drawn to the same vacuum by the fat hose. Under high loads, the fat hose loses its vacuum, raising pressure on its side of the diaphragm - however the other side stays at high vacuum due to the one way valve going to it. Once the engine has warmed up, the thermo switch opens allowing the vacuum to drop on the small lines side as well. Hence, while the engine is cold, enrichment under load depends on the small lines between the thermo switch, the one way valve, and the control pressure regulator maintaining low pressure conditions.

        The distributor advance is pretty simple (!), advance is determined by the pressure drop relative to atmospheric just ahead of the throttle body butterflies. When the air is moving fast, the distributor gets advanced...

        In the middle of this hose there is a little vacuum actuated switch with a screwdriver adjustable center (not shown). I always thought this was some mysteriously important bit of gear. Now I know it's just a sender for the upshift light control unit.

        There is a vacuum retard function as well, but only on vehicles with AC and automatic transmissions. I suppose this stops the engine from stalling when the car is coasting against the slushbox. This line is tapped in at the same source as the CPR fat hose (a Tee off connection #3)

        The AC functions are as follows - whenever the AC is on, the idle is increased through the air valve by letting some extra metered air around the throttle body to the intake manifold. The other line stores vacuum through a one way valve in a canister (three tennis balls) under the right fender, and when the heater control is moved all the way to the "cold" position an electrical valve uses this vacuum to close the recirculating flap.
    • - Suspension -
      Posted by: Pre95 (1154) on 2011-12-12 16:56:57

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      • Control Arm Bushing Replacement (Later style, 85-91)
        Posted by: Pre95 (1154) on 2011-12-14 22:24:24

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/bushings.htm
        Images: Originally from Huw's Audi Garage

        Faced with a life filled with a seemingly endless ritual of fighting nasty old metal sheathed control arm bushings on my 1989 90 Quattro, I went to the hardware store in search of a way to make a simple tool for removing them. All I needed was $5 worth of plumbing and a bolt I had at home. While building it and using it required a few tools, they are all generic things that any home mechanic will use over and over again.

        Tools used:

        Safety goggles! Not negotiable!
        Electric drill with some good bits (11/32 is required!)
        10 x 1.5 mm tap and die
        1" socket to drive die easily
        Air powered impact wrench for the die and to use the tool easily
        Cutting oil for thread making tools and eventual bolt lubrication
        Vise to hold things while making threads

        Simple hardware needed:

        2" 'close nipple'
        2" threaded cap
        alternatives to the above two items:
        short section of 2" pipe with threads on one end plus the cap, or
        short section of 2" pipe with 1/4" steel plate welded to one end
        3/4" coupling
        3/4" plug
        10 x 1.5 x 140 mm bolt - this is an A/C compressor mounting bolt, "N 010 495 1," if you want to one from an Audi dealer.
        A couple of washers - one should be extra large and thick, I think I used a subframe mounting washer.

        How to build it:

        Drill an 11/32" hole in the center of the 3/4" cap and tap 10mm x 1.5 threads in it. I could have used a 3/4" cap in place of the coupling and plug, but the plug allows for a much greater thread length, which I think will make this tool last a lot longer.
        Drilled about a 7/16" hole in the center of the 2" cap - big enough to clear the 10 mm bolt shaft.
        Make sure your 10mm bolt has enough threads, about 2", to pull the tool together far enough to remove the bushing. My spare parts box bolt needed about an inch of thread added to it with a die.
        Assemble the two separate sides by screwing the 2" cap onto the nipple or pipe section and the 3/4" plug into the coupling.
        Grind off any burrs or mold marks on the 3/4" coupling, since it is a very close fit in the control arm.

        How to use it:

        Put your washers on the bolt - a regular one against the head and the big sturdy one next.
        Put the bolt through the 2" cap
        Run the bolt through the bushing you wish to remove from the "outside" of the control arm wishbone
        Snug the 2" nipple up against the control arm, around the flared part of the bushing
        Place the coupling end of the 3/4" pieces over the bolt and thread the bolt into the plug
        Snug the coupling up against the bushing by hand tightening the bolt
        Important: Make sure the coupling is inside the control arm metal all the way around. This may require a little tweaking as you start to tighten the bolt.
        Tighten the bolt (I used an impact wrench to make life easier), keeping an eye on the coupling to make sure it does not catch against the control arm - it should get pulled inside the arm all the way around as it starts to push the metal sleeve on the bushing through the arm. Once it is moving properly, just keep going until the bushing pops out!

        I was surprised at how easy this was, the thing that makes it so easy is that the common plumbing stuff just happens to fit the bushing and control arm nicely. I am sure this could be done on the vehicle, too.

        To make it clear how this all worked, I have taken some pictures of the tool and its use.

        One picture tells a thousand words for the handy manly-man:

        Here are some more detailed pictures of the things you will need:

        I did this one on the bench, but I've done four under the car and it takes about 20 seconds to remove them:

      • Control Arm Bushing Replacement (Early style, to 84)
        Posted by: Pre95 (1154) on 2011-12-14 12:58:38

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/bushings.htm
        Images: Originally from Huw's Audi Garage

        A shot subframe and perhaps control arm bushing or two on my 1982 Coupe made me decide to clean up a subframe and pair of control arms and get them powder coated, in order to install them with all new bushings. Most of the job is pretty straightforward, but trying to force the control arm bushings in with my arbor press or vise was fruitless, it just looked as if I was going to tear the rubber eventually.

        Looking at the Bentley manual, it appears that one of the special tools squishes (tm) the bushing down in diameter so it will slide into the arm easily. Lacking one of these, I cut a 2" piece of 1.5" PVC pipe, then cut it lengthwise once. It's easy to press the bushing into this with a vise because it opens up as the bushing goes in - with a little help from a screwdriver. The second side is pushed in, till the bushing is centered, using a socket. When both sides of the bushing are in, I use a hose clamp with help from the vise to squish (tm) it closed tight. Make sure not to pinch the edges of the bushing - I used a screwdriver to keep pushing the bulging edge in neatly as I went.

        Then I made another tool like the first, only 1.25" long, to go around the inside of the control arm flange. This does two things - it allows me to put the stuff further into the arbor press to get a better grip, and also allows the bushing to pop all the way through without rearranging everything halfway through the job.

        I think the pictures explain this method far better than words ever could... it took less time to install one than it took to stop and take them!

        No special tools:

        It's easy to press the bushing into this 2" piece of PVC with a vise because it opens up as the bushing goes in - with a little help from a screwdriver.

        The second side is pushed in, till the bushing is centered, using a socket.

        When both sides of the bushing are in, I use a hose clamp with help from the vise to squish (tm) it closed tight.

        Make sure not to pinch the edges of the bushing - I used a screwdriver to push the bulging edge in as I went.

        When the hose clamp is closed it should look like this:

        Then I made another tool like the first, only 1.25" long, to go around the inside of the control arm's hole flange.

        Place into the arbor press (I'm sure a vise would work...) and push hard keeping everything centered.

        Did I say "Yippee" yet?
    • - Transmission / Clutch -
      Posted by: Pre95 (1154) on 2011-12-12 16:56:35

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      • Firewall tear on 4000/CGT/UrQ where master cylinder mounts-symptoms are no clutch dissengagement
        Posted by: Tony Hoffman (1624) on 2012-04-08 10:24:56

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        And pedal not returning to it's stop.

        This is caused because as a clutch wears it gets harder to push in. The firewall was not properly engineered for these additional forces.

        Look closely at the firewall where the clutch pedal mounts to it. Check for rust/cracks and have a helper push the pedal while you watch it. If it moves at all, you are starting to have flex/cracking that will only get worse. Time to strengthen the mounting point of the master cylinder.

        There are several ways to do this. You can buy an aftermarket bracket that bolts outside the firewall, you can reinforce the firewall yourself, you can reinforce the mounting point of the master cylinder from the inside, or come up with another solution. I prefer to reinforce them from the inside. Here is what I did:

        I built a bracket to go inside the car, and attach to the strong alluminum bracket that the pedals attach to. I also welded and redrilled the hole for the pin at the top of the pedal. Don't think I've owned a 4000Q that hasn't been at least a little worn there.

        So, without further ado:

        I started gy figuring out where to support the firewall from, outside or inside. After looking over the available options, I decided to support it from the inside of the car:

        Here's my first bracket I made. Pretty fancy, huh ;-)

        Quick close-up of the bracket:

        All done and supporting. This was in Petunia, which then got about 25K put on her before the accident. Never another issue from the clutch :)

        I've since done two more of these. All have been slightly different, but each does essentially the same thing. The only thing to be cautious of is the thickness of the steel that the master cylinder studs go through. If you go too thick, you will have to put longer studs into the master cylinder.

      • Slave cylinder and clutch hydraulics related issues
        Posted by: casem (113) on 2011-12-12 20:36:53

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        The hydraulic system for the clutch in your 4000 or Coupe GT will almost certainly cause problems at some point. This applies to 1985-1987.5 Coupe GT's and 1985-1987 4000's with 5 cylinder engines (4cyl cars have a cable operated clutch instead)

        If your clutch pedal is on the floor or doesn't return all the way to the top, best case scenario is there is just air in the line. Try bleeding it at the slave cylinder as follows: (slow method)

        Have a hose on the end of the slave bleeder and have it go into a jar with some brake fluid. Get a wrench on the bleeder. Have a friend stand in and help you there so he or she can manipulate the wrench when needed. Get in the car, open the valve, push the pedal down, leave it open for a bit, then close, then let the clutch pedal back up. Repeat as necessary.

        OR...you can bleed it with a power bleeder (fast method)

        If this doesn't solve your problems, perhaps your slave cylinder has failed. If you are getting fluid through the line into the slave cylinder but not out of the bleeder valve, the slave has failed. Replace. See HERE for clutch slave cylinder replacement instructions.

        If there is no fluid going from the master cylinder to the slave cylinder, either the line is gunked up or the master cylinder has failed. See HERE for master cylinder replacement instructions.
      • Clutch master cylinder replacement
        Posted by: casem (113) on 2011-12-12 20:34:50

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        This one is pretty easy.

        Use a 14mm open end wrench to remove the hard hydraulic line going into the end of the master cylinder. Catch the fluid with a towel or pan.

        Now, crawl under the dash. This part requires patience and or small hands.

        You'll see the rod attached to the top of the clutch pedal which goes through the firewall into the master cylinder. There are two 10mm (maybe 12mm) nuts that hold the master onto the firewall. Remove those. There is a clip that holds a pin in the clutch pedal/rod assembly. Remove the clip, poke the pin out with a screw driver or something. Remove the master from the firewall.

        Installation is reverse of removal.

      • Clutch slave cylinder replacement
        Posted by: casem (113) on 2011-12-12 20:26:50

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        Be prepared to have some fun with this one, not really.

        So your slave cylinder has failed, or perhaps you're replacing it as preventive maintenance (good job).

        The slave cylinder is located in the top of the transmission, under the steering rack. It's held in by a 3/16" hollow pin.

        First, set the E-brake and all that, don't get ran over by your own car. Place the car in 4th gear, it gets the shifter linkage mostly out of your way. Next, use a 14mm open end wrench to loosen the flexible hydraulic line going into the slave cylinder but do not try to remove the line. Just loosen it. Make sure you have a towel or pan under there, as you'll now be leaking brake fluid.

        Next, your car may still have the original tension rod that goes through the hollow pin (looks like a bent piece of coat hanger). Remove that with a pair of pliers or something if it still has it.
        If not, take a 3/16" punch and place it directly on the pin. Use a hammer to knock it out the passenger side from the drivers side. It may take some coaxing and lots of PB Blaster to get it started. Eventually you'll knock it out.

        Alternatively, pin removal may be easier for you if you take either of the front wheels off and use a crap load of ratchet extensions and a socket that fits your punch and use it to knock the pin out via the tie rod opening.

        Once the pin is out, remove the slave cylinder from the transmission. Once again, lots of coaxing via beating with a hammer, using a pry bar, and using lots of PB Blaster will help. Now that the slave is out, unscrew the slave cyl from the hydraulic line. This way you don't mess the line up.

        Installation is reverse of removal, just keep in mind you'll have to bleed the line when you put it back in. Also be sure to use some anti seize or anti corrosion lubricant on the part that fits inside the trans, it'll make things easier next time.
    • - Engine -
      Posted by: Pre95 (1154) on 2011-12-12 16:56:22

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    • - Interior / AC & Heat -
      Posted by: Pre95 (1154) on 2011-12-12 16:56:00

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      • A/C system upgrades:
        Posted by: Tony Hoffman (1624) on 2013-07-11 15:26:45

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        • White cover box refoam.
          Posted by: Tony Hoffman (1624) on 2013-07-11 15:37:27

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          This is necessary for max A/C system performance. The foam on the recirc door disintegrates.

          The system in the 4000/CGT/UrQ requires recirc for A/C. Otherwise, if outside air is pulled in, it doesn not get pulled past the evaperator.

          You will pull the screen off the side of the box, if it's still there (hasn't been on any of my cars). There are two screws with 8mm heads. Unscrew them. Then, on the other side of the box, there are two more. One holds the recirc solonoid in place. Pull them.

          The box is held to the body with some sticky butyl, so it will be pretty stuck. Just have patience, it will come loose. The blower motor sticks up a bit, you will need to wiggle the box around a bit to clear that.

          When you pull it, there is a black twist plug that holds the flap in place. Twist it (I think it's 90 degrees) and pull it out. Then, you will have to remove the rectangle piece of plastic and clip on the other side.

          There is a clip on the center portion that contorls the flap. Pull that clip, then the linkage.

          At this point, the flap will come out. Clean it completely. Now you will nead new foam, I bought 1/4" thick X 3/4" wide heavy density foam from Lowes/HD to use for this.

          Replace the foam on both sides of the flap, then reassemble.
        • A/C compressor, change to later style rotary compressor.
          Posted by: Tony Hoffman (1624) on 2013-07-11 15:29:22

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          The advantages of this style compressor are twofold. First, they require slightly less power to run. Second, they pump a bit more refrigerant at a given compressor speed.

          This conversion will require several things to complete:

          Swap in the compressor from an Audi 80/90, you will need the compressor bracketry from a 5-cyl. The compressors are the same on all of them, though.

          You will need the compressor to low side line. Don't recall for sure on the high side what was done, but grab the one from the donor car and you will be good to go for sure.

          Replace the reciever drier, pull vac on the system, and charge it up.
      • Power Door Locks
        Posted by: Pre95 (1154) on 2011-12-15 01:58:03

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        From: Huw's Audi Garage
        URL: http://www.humanspeakers.com/audi/power-locks-85.htm
        Images: Originally from Huw's Audi Garage

        There are basically two systems of pneumatic central locking on Audis of the vintage that I deal with - the earlier cars are controlled by the drivers door lock, and the later ones by both front door locks.

        The early ones (5000/100/200 before 1984, 4000/Coupe/Quattro/80/90 before 1988) use a pump/controller unit with a three pin connector. Here is an electrical and pressure line schematic of the single control system:

        Remember that since the control switch is in the drivers door and the pump is buried up by the passenger side trunk hinge, the wires are a lot longer than this picture might make it look. Also, the pneumatic lines snake all over the car, under the carpet, and into each door (and the trunk lid) to operate the actuators.

        The first step in troubleshooting is to determine whether your troubles lie in the electrical or the pneumatic side of the system (or both...). If you can hear the pump humming away when you lock and unlock the drivers door, but nothing happens to the other door locks, it is most likely related to the hoses connecting all the lock mechanisms, the pneumatic actuators in the doors, or the pump no longer creating effective pressure. If you hear no tell tale sounds, then the first place to look will be the electrical portion of the system - the switch in the drivers door actuator, the fuse and wiring, and the actual response of the pump to appropriate signals.

        Location of parts:

        Main Fuse: #19 under the hood. 10 amps.
        Control unit & Bilevel Pump: is usually buried in the top front right side area of the trunk, encased in sound deadening material.
        Master Actuator: in the drivers door, below the lock knob. Most if not all type 85 systems do not run a pneumatic line to this actuator. In the diagram it is shaded light grey, since I think some of them do.
        Slave Actuators: in the passenger door under the lock knob, and if applicable, in the rear doors and trunk lid.
        Pneumatic hoses: under the back seat, under the carpet, and snaking into every door that matters.
        Pressure Accumulator: usually near the pump, in the trunk.
        Most of the wiring: should be in the loom mounted under the carpet on the left side of the cabin floor.

        I think that apart from the most cursory checking (like, is the fuse there?), you can count on opening up the drivers door and digging under the trunk liner to get to the control unit/pump. If holding your trunk open while trying to remove the pump is a chore, perhaps replacing those dead trunk struts should be the first order of business? They cost about $20 each and should be replaced, not lived without. What is the point of a luxury feature like power locks when your trunk won't even stay open on its own?

        I would recommend doing all this work with at least one window wide open - that way, you can always get back into the car if you somehow manage to lock all the doors so well that you can't unlock them!

        When you extricate the pump, you will probably need to unscrew its ground connection to get good access to the 3 pin connector and wiring going to it.

        To test the pneumatic lines, disconnect the main feed from the pump and apply vacuum to it to lock the doors, and pressure to unlock them. A Mity-Vac type tool is best for this. If your system fails this step, examine all the pneumatic parts for leaks or disconnections. Most of the lines are a hard green plastic tubing. At the junctions there will be short pieces of fairly durable rubber hose, and Y's, T's and such to connect the branch lines. Check the accumulator thing, which is a bright green sphere or cylinder. Check all the door actuators, which are usually blue oval things, about 3" by 1", with a collapsible boot type thing on the top attached to a metal rod linked to the latch mechanism.

        Since it is possible for a very sloppy door handle replacement to have displaced one or more of these rods, make sure they are all in place, too. Simply locking and unlocking the door in question manually, while watching the actuator, will show whether these are intact.

        Repair or replace any faulty components in the pneumatic system after doing all the troubleshooting. It is quite possible that at some point, the electrical systems failed, and someone "opened up" a connection to stop the locks from all pushing each other up and down when operated. Finding such a disconnected part may simply indicate that you have other things to fix as well.

        If your system exhibits electrical malfunctions, test it the following way:

        Start at the beginning - in the fuse box. Fuse 19, 10 Amp, should be getting battery voltage (always on no matter what key position) on its hot side, the fuse should be good, and the battery voltage should then be present on its fused side as well. If the fuse is blown, it may indicate a pump drawing too much current, or a wire shorted to ground somewhere.

        If that checks out, make a note that the wire leaves the bottom of the fusebox at M30az, which I think is a single tab connector. You might need to check that, too, but it is unlikely to have fallen off.

        A red/black wire then proceeds through the spaghetti mess under your drivers side dashboard and into the door. Yup, it's time to remove that door panel, if it's not already off.

        This wire goes all the way to the drivers door lock master vacuum actuator. There will be a three pin connector at the actuator. Undo it. Use your voltmeter to check for 12v at the center (#2) terminal. If it is not there, then this wire is probably broken in the door jamb. Make a note of that. (If your fuse was blown, you should be checking for continuity between the "fused" side of the fuse holder and this terminal - and ground, since a short would also mean continuity to ground. If your fuse was blown, also try measuring that resistance to ground while moving the door around.) The reason I keep saying to "take notes" is that you should troubleshoot the whole system before digging out your repair tools - that way you will know what to be expecting to fix, rather than finding one more thing after another as you go.

        Test the actuator switch itself, for continuity between pins 2 & 3 and pins 2 & 1, one should correspond to the locked, and the other to the unlocked, position.

        Next, the switch in the actuator has two other wires leaving it. Check the continuity between pin 1 of the door connector and pin 1 of the pump connector (and ground, to check for shorts), ditto for pins #3 on each. There should be no resistance (zero ohms) between the pins, and infinite resistance between all of them and ground.

        If you do have problems with the wiring, the most likely location for breaks/shorts is in the drivers door jamb boot, but they could be elsewhere along the way if you are really unlucky. If you are going into that boot to fix breaks, one, remember to replace a section of wire about a foot long to keep your splices in the door and in the car (under the little kick panel - pull up its little bit of carpet to reveal its fixing screw, and undo the hood release handle screws as well) and not in the part that flexes, and two, to look at all the other wires for damage while you're in there. If any of your door controls don't work, their wires may also be hurt. Only cut one wire at a time, to avoid confusion in the splicing process.

        You can test the pump by applying 12 volts to pins 1 or 3, one at a time, while grounding the brown wire. It should alternately cycle as a pressure and vacuum pump, running for about 30 seconds in each mode. If the pump works fine, a further test of the wires (green/blue and green/red) from the actuator to the pump connector is to try running 12 volts along them to the pump to make it work, remembering to keep the pump grounded. Definitely do not zip the project up until that pump is consistently performing both its functions. If needed, another pump should go in rather than the one that does not work right.

        By now you have probably found one or more differences between "what should be" and "what is," and hopefully you have been taking notes of where the discrepancies lie. Fixing all of them at once is easier than doing them one at a time and still finding that things do not work. That is why you do such an exhaustive troubleshooting process first.

        Once the door is wired properly, and the fuse is good and delivering 12v to the master actuator, you can further test it by measuring the voltage to ground at the connector for the pump unit. Pins 1 and 3 should each register 12v in turn, when the master door is locked and unlocked. If your pump seems to be in good working order, plug it back in and ground its brown wire (it may be difficult to attach it to its original location while troubleshooting, so use a jumper wire). See if it cycles properly upon locking/unlocking the drivers door. If it does, plug the (repaired) pneumatic line back into it and test the system again.

        When you are certain the system is working 100% (no less!) of the time, then you can replace all the parts where they belong. I recommend testing the system at each stage of reassembly to ensure against accidents - if it suddenly stops working, at least you know you only did one thing since it last worked. Make sure the brown wire from the pump connector is properly grounded as you reasemble everything, at its original location, or a new one of the old one is nasty looking. The sheet metal screw, the ring tab, and the sheet metal of the body should all be shiny and clean, free from dirt and corrosion. Use some dielectric grease on it (and the door and pump connectors) to keep it that way.

        Have fun and good luck!
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