High Idle / Idle speed motor
Hi
My idle speed slowly increases as the car warms up and tops out at about 10000 rpm when hot and cooling fans cut in. I know its not super high but I'm trying to get to the bottom of it, its not throttle linkages or switches. If I disconnect the idle speed motor and apply 12v/ground to the appropriate pins the idle speed motor fully closes and the idle drops to around 800
So my question is, would , under normal circumstances, a fully closed idle speed motor mean that the engine would die through lack of air ? Do I have a vacuum leak of sufficient size to keep the engine running ? Or is it supposed to be fully closed and the signal from the ECU isn't correct ?
Thanks