RE: 91 200q boost problem

["Paul C. Waterloo" <74543.407@compuserve.com>]

>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.

Don't know, but I hope you started checking components. The throttle
potentiometer is very easy to check, then you also need to check for opens
between it and the ECU. All very simple checks with a multi meter.

You're not getting the full boost when it is not running correct, are you? If
you are, then the ECU isn't backing the boost off, which it will do if it sees a
bad input from one of the components in the system.

>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. 

The only thing I would check is to make sure the cam timing is set correctly
after replacing the belt. Maybe they are off a tooth....don't know though.

>If anybody has had this problem, or has any good advice. I would
>be very grateful.   

HTH, BTW, if you live in the Chicago area, I'll look at it for you...

Paul

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Paul Waterloo
Riverside, IL

91 200q

EMAIL: 74543.407@compuserve.com
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