High idle when warm - TPS check?

[Lordjimimac]

Hi all, my car has developed a 2k idle when warm - starts lovely when cold. I’ve checked all hoses and cleaned ICV and no joy. If I touch the underside of the TPS and there is wet oil there - does this indicate that I need to clean that? Is there any way to test the TPS is faulty without taking it off and without a voltmeter? (I lack both the skill and equipment!) big thanks for any thoughts here - bought the car last week - minter but already a glitch I’m keen to iron out so my love for it can grow!

[Brianmoooore]

If t's idling at 2k, then the engine must be getting getting sufficient air to do so. It can get this excess air by the throttle butterfly not closing properly, the ICV not closing enough, or by a considerable air leak.
First thing to check is that the throttle butterfly closes tight against its stop.
Engine type and date would help!

[Lordjimimac]

Thanks so much for your reply Brian - very much appreciated. It’s a 1991 320i with the M20’s engine. I followed the advice in the very helpful tech section and tested the voltage on the TPS - the idle was working but the circuit remained unchanged on pins 1 and 3 when at WOT - I wonder if this could be causing the high idle? I imagine not as the pin 1 and 2 check was fine?