she starts, she won't run - 1990 200QA

[Ameer Antar]

If you suspect the fuel distributor, try adjusting the airflow plate by hand
while it's running and see if you can keep it running by adjusting the plate
height. If you take out the air filter, you should be able to access the
airflow plate from the bottom. It may take more than a few tries to adjust the
plate properly with a dying engine.
 
Has the car sat for a long time before this? Gummy fuel deposits are the
biggest problems with fuel distributors. Other than that, they should not have
major issues, unless you have garbage getting past the fuel filter (you'll want
to check the injectors and the rest of the fuel lines in that case). If you can
get the engine running by adjusting the plate, I think it would have to be a
vacuum leak or a sticky plunger in the distributor. My bets are on a vac. leak.
That's just too common for these cars, and the problem is there are so many
hoses and hidden locations these could be in. With these cars, it pays to
remove most of the hoses and pipes to inspect each one very carefully in the
light. Some hoses even look fine, but if they're soft, they can be leaking air
through very small cracks. Try flexing the hoses after taking them out.
 
Another thing to check: With the engine running, taking of the oil cap should
kill the engine or at least make it stumble close to stalling. If you don't
feel much difference with the oil cap off, there's definitely a vac. leak
somewhere. If you can really rule out leaks, then you might want to take the
distributor off the air cleaner housing and check the plunger for consistent
movement over the entire range. There will be pressure on top of the plunger
unless the fuel lines are taken off. Careful, the plunger can fall out if there
isn't a safety catch washer. Keep a finger on it just in case when pulling the
distributor out. If you do this, you'll probably want to replace the o-ring
between the distributor and airflow plate.
 
Best advice is just to take your time ruling out possible problems. Let us know
how it goes. Good luck.
 
-Ameer 

-------------------- Original Message --------------------
 >
> Message: 9
> Date: Fri, 19 Jan 2007 22:58:33 -0500
> From: "David Michael" [adavidmichael at gmail.com]
> Subject: she starts, she won't run - 1990 200QA
> To: quattro at audifans.com
> Message-ID:
>     [a8fd8d050701191958i39393b84s7e64ae1a222ad034 at mail.gmail.com]
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Well, after 12 years of owning a type44, the love affair may be ending. Our
> beloved 1990 200QA is seriously misbehaving. When cold, its starts
> immediately, and then just as quickly dies.
>
> I ran through the archived, and found a posting from someone who had
> exactly the same problem. Turns out that someone was ME - about 8 years ago.
> The problem then was a vacuum leak through the valve cover gasket.
>
> Unfortunately, not so easy this time. I rpeaced the gasket last year. The
> car has been at an experienced Audi mechanic for three weeks. They have
> checekd all the sensors, all the pressures and all the control signals,
> found no vacuum leaks and they said they all checked out nominally. What
> they told me is that there seems to be something in the fuel distribute that
> is creating too lean a condition, but the only way to be sure was to replace
> it. At which point I said stop. This all came on rather suddenly - the car
> started fine through the 8 winters an all through the summer and fall. But
> when it got below 30 (finally), then it started misbehaving.
>
> I am not really asking for advice hear, since I no longer have much time to
> got out and fiddle with the car. I will check the valve cover gasket again,
> since but short of that, I am stumped.
>
> I am bummed.....
>
> Dave
> 1990 200QA
>
>
> ------------------------------
>