Can't seem to adjust idle speed?

[Error404]

Bit of an odd one, took the inlet manifold complete with throtte body attached off the 7A today. Refitted everything but idle was low, about 600rpm. Tried to reset it by disconnecting the ISV and turning the idle adjustment screw on the throttle body but it didn't increase the idle speed.
I can adjust the idle down enough to stall the engine, but it won't pick the revs up beyond about 650rpm, but when i wind the screw out i can hear the increase in air bypassing the butterfly but the revs don't pick up
I checked for vacuum leaks and also disconnected the idle switch but can't seem to get my head around this.

Any ideas guys?

[mcandmar]

Dunno, thats a strange one. Sounds like a car with an unplugged maf, possible the rubber intake bellows might have torn where the crank case breather enters it, basically air entering between throttle body and maf so the ECU dosent really know whats going on. If you were out working in the cold and dark double check everything is re connected, i have a habit of missing things when i want to be inside and warm

[Error404]

haha, yes well i did managed to get the valve cover gasket kinked so it all needs to come apart again

I did have pretty good going over the intake trunk as I split about 3 of those now over the years removing and putting back on

I also wondered if it was a vacuum leak through the idle valve itself, I guess there is a seal or gasket in there somewhere.

[UrS4boy]

N71 Idle Speed Stabilization Valve (ISV or ISS Valve) Info

This might help (or not):

http://forums.quattroworld.com/s4s6/msgs/21853.phtml