high idle

[comnigo]

Diagnosing a high and inconsistent idle issue on Shelby Lancer 228 5speed. I think I have narrowed it down to the AIS as I tried a spare and the idle seems to not get stuck around 1500 and slowly fall as it was doing with the first AIS. Idle is still a little erratic ie...not smooth. If I tap, with the handle of a screwdriver, on the AIS it seems to smooth the idle out at times and sometimes it causes the engine to race to 2500rpm or more and sometimes the tapping causes the engine to stall...why? is this AIS on it's way out also? any help/advice appreciated....nick
apology if this is in the wrong section

[raccoon]

clean the AIS passage way out really really nice, I had a problem when then plunger would get stuck along the way on a burr from the factory.


I would test for leaks by blocking the AIS passageway before the butterfly valve, if it keeps running, you've got a leak somewhere, most likely on the throttle body to intake gasket.

[cordes]

+1 for cleaning the AIS passage. I usually spray it thoroughly with carb cleaner. Check for any other vac leaks in the vacuum lines too.