Blue44

Please help!! Runs like doo doo.

I bought a 1987 Coupe GT cranks but wont start, Sapphire Blue, Digital dash, 5 speed. 113k miles

What I have done to the car.

Checked all fuses

I set the timing with a timing light to -6 +-2 degrees.

Put new spark plugs, cap and rotor.

Put a new engine computer in it.

Removed and check spray pattern on injectors. They are perfect with no dripping or abnormal spray pattern.

Put a new Idle stabilizer in it. old one was rusty.

Put a new ignition switch in it. Old one was cutting out.

Put 4 gallons of NEW premium fuel in it.

Put a new fuel pump relay in it.

Reset the idle micro switch on the bottom of the throttle body to engage when the throttle is closed. Ohmed it out. 0 ohms of resistance.

Took fuel distributor completely apart. Cleaned with solvent. Put new seals in the distributor. Installed it back in the car.

Whats happening...

When I am able to get it started, after I clear out the flooded fuel, it runs extriemely rich.

I set the idle screw on the throttle body to one and a half turns off of all the way closed; A good rule of thumb I have heard from a master Audi tech.

I checked the Idle stabilizer and found that it's not getting any power from the ECU. This would obviously cause a rich condition although It's rich even off Idle at 2000 RPM.

I have adjusted the 3mm allen screw in the fuel distributor to lean it out. Still runs rich off Idle.

Please help!!!

Rogviler

Sounds like you've done some extensive things... What about the basics like checking for vacuum leaks? I mean really check, like with smoke (not cocking about with spraying carb cleaner or similar nonsense).

Does anything change if you completely remove the idle stabilizer? I wouldn't suspect it for a richness issue myself (unless it's introducing unmetered air somehow), but it's easy to test that.

What about the oxygen sensor? Again, easy to test.

Lastly, have you checked the cold start valve/thermo time switch? If it's leaking or if the switch isn't telling it when the engine is warm and it's not shutting off, both of those will cause it to be rich.

One other thing is the O-ring on the idle screw. Those go bad and then extra air will get in that isn't being metered.

I know those are all simple, but with CIS it usually is a simple problem...

-Rog

Blue44

Thanks Rog!

I haven't had a chance to check those things yet. I did check for vacuum leaks, not with smoke though. I did get the Idle Stabilizer online though! No change. I checked the Mass air flow meter travel and found that it hangs up at about 30% open. I also checked the variable resistor on the side of the mass air flow meter and found that it does not work. It reads a constant 4k ohms through the full travel of the air plate. Perhaps I'll call Shokan 1-800 All Audi for these CIS E parts

Inline5fan

Is it an 87 or an 87.5 with the 2.3 liter?

I can't speak for the 87.5 Special Builds, but if your car it the early 87 model, have you checked the fuse for the fuel injection? If you take the cover off your fuse/relay box, there will be a fuse that is up against the side of the box (side closest to the fender), perpendicular to the direction of how all the other fuses are in the box. This fuse is often mistaken as an "extra fues" and sometimes is removed when trouble shooting and not replaced. You should be able to look down and see the prongs that grab the fuse. The other recepticals for fuses along that side of the box won't have the prongs. Check that fuse and see if maybe that is your problem. It may have been removed or maybe it has blown. Worth a look.

If your car is an 87.5 and has the three wire oxygen sensor, I would maybe check that the O2 sensor is working properly. The early cars have a single wire O2 sensor, and normally don't have much affect on the runability of the car. The three wire though, does. You could try unplugging the O2 sensor and see if the symptoms change.

Hope that helps.

Cheers,

Ted
82 4000 4E
86 Coupe GT
90 V8 quattro

socalclimber

Do you have the Bentley manual for your car? It's a great resource, really essential for working on Audi fuel injection and ignition systems.

Idle stabilizer doesn't alter air-fuel mixture, it only bypasses (meters) volume of air around a closed throttle plate during idle.

How are you checking air-fuel mixture to know it is rich? Normaly it is checked by plugging in a test harness (VW1315/A) and measuring mA current for the Differential Presure regulator (the gray plastic thing) on side of fuel distributor a la Bentley.

Good points on measuring DPR current (called CPA current in this article)
http://audi.humanspeakers.com/timing2.htm

Granted, if it is nearly a no-start, it's hard to measure this mA current and be meaningful if it won't idle. Have you tried removing air filter and moving/holding air flow meter with your hand to keep it running either making it more lean or more rich, it won't take much to change A/F ratio drastically, even 1/16" movement is a lot at idle. This lever (sensor plate) cannot bind anywhere or something is very wrong in fuel distributor and/or sensor housing.

The variable resistor you mention is the Air Flow Sensor potentiometer (black plastic) and enriches A/F mixture during acceleration (possibly only when cold)--I wouldn't worry about it--it doesn't play a big part, and probably is not your problem. It sounds like you are having basic A/F mixture metering problems (blown DPR, bad wiring to DPR, way off initial mixture with 3mm screw, O2 sensor dead or O2 signal not getting to ECU).

Some good discussion on CIS-E and fuel injection issues
https://www.audiworld.com/forums/sho....php?t=2796735

CIS-E Fuel Injection VW training guide (applies to Audi also)
http://www.csupomona.edu/~bvnorum/ca...521-124-00.pdf

Good luck, sounds like you've already checked a lot of things.

Blue44

Thank you Brent and Ted. I have the car running after replacing the whole fuel distributor assembly with a used one from Shokan. I also replace fuel filter and fuel pressure regulator. Now I have to tune it. It's got plenty of power although at wide open throttle it bogs a little. I'm going to start with the basics first. Just got it running

socalclimber

Blue, glad to hear it! Now just give it some TLC and fine tuning.