I recently purchased an s5 turbo II thats a bit of a basket case but its coming along.

I have a lean misfire at idle, and as best I can tell Ive eliminated any major vacuum leaks and metered air leaks as the source of the problem. (smoke machine)

When ever I turn the AC on the miss seems to all but disappear.

Im curious if theres more to the AC idle kick then just the solenoid on the rear of the intake manifold? My solenoid has both its wires broken off does anyone know what the default position of the AC kick up solenoid on the rear of the manifold is? open/closed (idle up/down)?

When I got the car the vacuum lines were a mess but Im fairly sure Ive corrected 99% of the lines.

I guess what Im looking for is what all exactly does the AC button command to happen? is the idle kick up purely a metered vacuum leak or does the ECU have some sort of AC enrichment command also? any other things it may do when ever the AC is on that Im not aware of?

Thanks for any help in advance.