Audi 200: idling high after gearbox work...

[Gerard]

Got a call from someone now regarding his 1990 Audi 200 (MC engine) FWD
automatic. He has had the differential changed and gearbox work done.
Get's the car back and it is idling around 2000rpm and, although that
might be fine for an F1 contender, I don't quite think it is the kind of
attitude a 200 should be doing. :)

Now, I can't sort of give advice over the phone and I can't look at what
might be going on when the car is so far away. I can only think of it
being a faulty ISV or something was not put back on properly when the
auto tranny went back in. Like maybe the linkage is badly set.

Any tips on what to look for would help, and I can relay the info to
him. Car was idling perfectly before going to the tranny shop.

Thanks.

G.