Re: increasing idle

[scott chaney <scott.chaney@mci.com>]

George,
    I once had a (cough) Z28, with the tuned port injection. I haven't
had much experience (yet) working on the Audi system, but I had a
similar experience with my Chevy. The throttle body has the butterfly
valves very similar to that of the Audi. I had an increasing idle that
would sometimes reset if I tapped the accelerator quickly. What I
eventually found was, in the throat of the throttle body, the coking
behind the butterfly valves was not allowing them to close completely
when the throttle was let up. There was a solid lip of this black (and
very tough) material built up which I removed by taking the throttle
body off of the car and scrubbing with a solvent, I don't remember what
kind. After removing this build-up, the car idled fine. Maybe some of
the other listers will have an input on this. It's a cheap fix and easy
to spot. I may be way off though....

HTH
Scott Chaney
87 5ks (project car)
88 VW Quantum