jumpy idle

[E30godz]

after driving a bit enthusiastically, the idle goes from about 500-800 in a regular fashion when coasting to a stop...when at a stop it levels out for the most part...what gives?

[Erick]

Idle control valve maybe?

My car has unstable RPMs when at neutral..... I've narrowed it down to the ICV.

It could also mean a vacuum leak, but in my case, it happens once in a while ( 50% of the driving time ).... if it was during the whole driving time, I would guess a vacuum leak.

So check for those 2 things.

Also, anyone that reads this, is it worth buying a used ICV? I'm almost swapping the white's ICV with the one on my black one....... father wouldn't be too happy though.... seeing how my brake fluid sensor suddenly stopped lighting up for no good reason and his now does