car won't idle...

[Richard van der Hoff]

I don't know if anyone is at all interested, but I thought I'd record for
posterity the fact that I finally got my ISV sorted.

The car is a 1991 2.0L coupe; engine code 3A.  The symptoms were that
lifting off the throttle would cause the engine to stall.

The (now obvious) solution was that the ISV was sticking; I'd actually
rejected this as a possible problem because, as far as I could see, the
valve was actually moving about ok.  What I got was a valve that was about
a quarter of the way open when disconnected and closed when powered.  It
turns out that the valve is actually supposed to go *through* closed and
open on the other side (IYSWIM) when powered, so it was only going
halfway.  The thing that surprised me was that the valve does this thing
of being slightly open when not powered at all - when you might expect it
to be fully closed.

I eventually took it back to the independant dealer who sold me the car,
who scrubbed the valve clean and all was as good as new.

So the story ends happily.  I'd like to thank Huw and the other guys on
the list who offered helpful advice.

I would *not* like to thank Vindis Audi of Cambridge (UK) who charged me
£60 to tell me that it was the throttle switch, and had I not stopped them
there would have gone on to replace the throttle switch (est. cost £230 -
for two microswitches!), and when that didn't fix the problem, who knows -
replace the ECU, the engine, the whole sodding car?

I really resent this approach of just replacing expensive bits until the
car magically works.  In this case getting Audi to fix a problem that the
local independent guy fixed in his lunchbreak as a goodwill gesture would
have cost me many hundreds of pounds.  It's not just Vindis's fault - I
went back to reclaim my £60, and Audi's diagnostic procedure is somewhat
unreliable. I'd expect better from Audi. Still, I've learnt a lesson, and
Vindis have lost a potential future customer.

Well, I'm sorry that what started out as a technical account turned into a
rant, but I wanted to get that off my chest, and warn others of the
dangers of Audi franchises...

Thanks again to audifans...

Rich

PS: my ECU still doesn't give out blink codes.  Think there's a fault with
the line driver in the ECU ... will investigate at some point.