What should it be idling at, and how does it work.

[TheKoose]

Hey guys

Just so i can work out what im dealing with. What should a 1987 325i idle at when cold, and once warm? Also what decides what it should idle at, , does the idle control valve mainly work when cold?

[DrBen]

hi koose,

Mine is an 89' but it idles at around 750 when warm and about 900 when cold - don't know if this is right though!

[abelai]

So yours is an early sport with motronic 1.0 and an ICM running the ICV? The ICV controls the amount of air going to the engine but can struggle if there are inlet leaks. I think your model also has a cold start injector aswell to enrich the mixture. Warm idle should be around 750rpm cold around 900rpm.

[TheKoose]

Thanks guys!