Hi there.
I am having some trouble with my 1991 525i m50. After it has warmed up for a few minutes and the idle drops, the engine runs rough, rough enough to shake the car. The idle is steady. I have tested for air leaks and can't see any. I have also checked and cleaned the ICV - this seems to be working correctly when applying a voltage to the terminals. The resistance across the terminals is also inline with what Bentley has to say. The airflow meter and TPS also seem fine. I've had the ecu read and no error codes are being logged.
I can unplug the throttle position switch, open the throttle and get it to idle quite low without any shaking.
Can anyone give me some ideas on what this might be?
Cheers,
Alistair
(Hastings).
