car won't idle...

[Richard van der Hoff]

The saga of my ISV continues.  The audi dealer swears blind it's the idle
switch (and wants to charge me £230 for fixing it!).

Personally, I think he's talking crap, and just wants to charge me a
fistful of cash, but can anybody give me a description of what it's
*meant* to do?

As far as I an see, the throttle-position sensor has three pins; 1-2
close at closed throttle, and 2-3 close at WOT.

Reasons for thinking the closed-throttle switch is good are:

1. a multimeter across pins 1-2 shows healthy switching, and a voltmeter
on pin 1 shows 0V at closed-throttle, 12V at open throttle

2. while the car's idling, opening the switch (by disconnecting it) causes
the engine to rev higher

3. no combination of jumpers across the socket, in an attempt to
mimic a closed throttle, make the ISV work properly.

Tomorrow morning I'm going back to the dealer, where he's going to show me
exactly what he did to justify the £60 he charged me for his diagnosis,
but in the meantime, I'd be very interested to know if anybody has any
ideas.

Thanks again,

Rich

PS: And he blames my lack of blink codes (see an earlier post) on a faulty
ECU. Don't know if he's talking crap there too, but either way it pisses
me off.