RE: 20V acceleration loss

[Ralph Poplawsky <ralphp@cellport.com>]

Larry:
Thanks for the interesting advice.  As a matter of fact, my fuel pump
becomes very noisy at high temperature - even so that I can hear it in the
vehicle after shutting down and restarting hot.  I have wondered whether my
pump is getting weak.  Did you experience the noise with yours?
Ralph

At 01:18 PM 7/31/97 -0600, you wrote:
>Ralph,
>Your problem sounds very familiar to one I experienced with my 87 5KCST.
>I found that the problem was caused by a plugged inlet screen on the
>fuel pump.  I found the fault by monitoring fuel pump pressure under
>conditions that produced the problem.  The pump screen had a film of
>what appeared to be silicone sealant covering it.  I expect the film
>came from a batch of contaminated fuel.  The problem started as a sumble
>and miss at full throttle on hot days.  It progressively got worse and
>one day I found myself stranded between two hills on a hot day.  After
>the sun went down things cooled enough that I made it home for more
>troubleshooting.  I won't go into the detailed explanation of what was
>happening but it all makes sense.  The main fuel filter could produce
>similar problems if plugged and that is the first thing I'd try but
>getting at the pump and cleaning the screen isn't too hard if Audi
>didn't change the tank design between our models.  I made my own tool
>for removing the pump retainer and did the job in less than an hour.
>
>Try my suggestion since it won't cost much and could solve your problem.
>It took me two months to track the solution down on my Audi.
>
>Larry
>If you don't care where you are, you ain't lost.
>87 5KCST
>84 4KS
>95 F-250 Powerstroke 4x4
>91 Suzuki Sidekick 4x4
>84 S10 4x4
>67 Porsche 912
>71 VW convertible
>
>> ----------
>> From: 	Ralph Poplawsky[SMTP:ralphp@cellport.com]
>> Sent: 	Thursday, July 31, 1997 9:27 AM
>> To: 	quattro@coimbra.ans.net
>> 
>> Can anyone help me?  My '91 200TQ 20V has acceleration loss and the
>> dealer
>> may own my house before it is fixed.  The symptom is as follows.  The
>> car
>> runs like a top up to about 1/2 to 2/3 throttle.  After that there is
>> intermittent power loss varying from a 'missing' feeling to cutting in
>> and
>> out to stumbling along and hardly accelerating.  If I back off on the
>> throttle when this happens, the engine smooths out and acceleration
>> actually
>> increases.  The problem appears to be worse in hot weather.  The boost
>> gauge
>> reads full boost.  Repeated acceleration runs sometimes result in
>> temporary
>> improvement.
>> 
>> Some background:  Several years ago, there was a similar problem, but
>> with
>> boost loss.  The dealer spent $5000 (in warranty) swapping parts to no
>> avail, and finally figured out (from the factory) that the cam timing
>> was
>> slightly off, the computer was sensing too much advance and shutting
>> down
>> boost.  The current problem began after the 60K mile service at which
>> time
>> the dealer replaced the timing belt.  I don't know if the current
>> problem is
>> related to cam timing or the 60K service, but I'm suspicious.  
>> So far, my dealer has charged me $250 for a new O2 sensor which has
>> not
>> fixed the problem.  He wants the car back to 'go further' but can't
>> really
>> say what that means. The owner of the dealer suggested that the
>> regional
>> service rep would be in, so why not have him look at it.  So, I gave
>> him the
>> information and later heard from the dealers' service department that
>> he had
>> nothing to say about it because he is only interested in 'in-warranty'
>> vehicles. 
>> 
>> If anybody has had this problem, or has any good advice. I would be
>> very
>> grateful.   
>> 
>
>