e30 M40b18 VERY high Idle on Cold Start

Hi Guys

Please can somebody assist

When I first got the car the cold start worked fine with the ldle at just over 1000rpm and then dropping after a minute or so to around 850 - 900rpm. This was perfect.

However, since 2 days ago the cold start idle jumped to about 2000rpm and only drops to around 1500 - 1000rpm after a longer period.

It only seems to settle at the usual 850 - 900rpm after the engine temp gauge goes up to mid way and this will be after driving for a while.

I've cleaned the ICV and reinstalled but it still does the same thing. (idling high)

Is there anybody who has experienced this and has a fix for it?

Some googling also lead to a possible vacuum leak issue (I tried checking all the pipes leading into the intake/throttle body by eye and couldn't see anything out f the ordinary by means of noticeable tears and/cracks

Assistance will be INFINTELY appreciated

Looking forward chaps
 

Nikhil

Honorary ///Member
Howzit bud,

Over and above what you've mentioned I've also seen this issue as a result of a sticky airflow meter
 
I'm in Pietermaritzburg... did the cleaning this morning. Cleaned the throttle body while I was at it.

High idle still persists.

Sent from my SM-A305F using Tapatalk
 

patt

New member
Hi guys, i have a f30 320i car has rough idle loose power and misfires at times.
we have changed spark plugs,coil packs, measure fuel pressure,change valvetronic,throttle body, checked oxygen sensors and still no luck. No error code picked up.
Anyone experienced this and what was the fix. Thanks
 

Jeremy.d

Active member
Hi Ahmed.
I've had a similar problem on my m40b16 before. I had to change the airflow meter. They're not easy to find in good condition, and in fact the one I have currently isn't perfect either, but my recommendation would be to change it if possible.
 
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