M40 all over the show

[Oxford318]

The cambelt on my M40 engined 318i went and as a result bent a few valves! This has all been repaired and put back together. However, on starting it revs around 1300rpm and bobs up and down the rev range. It drives perfectly well and the problem seems to go away when warm. Any ideas anyone?

Cheers

[Ronnaferd]

I've seen the high idle at startup on another car but it seemed to go away once the engine was warm...I don't think this is normal but if it goes away when warm I'm guessing just live with it. But what do I know :dunno:

[gwumpkus]

mine does that too..and its due to a faulty AFM...damned vane meters,... i'm saving up for an MAF conversion..

[Oxford318]

I don't wanna sound stupid, but what's an AFM?

[LuvThatSam]

I don't wanna sound stupid, but what's an AFM?




Air Flow Meter!!!!!!!!:thumbup:

[alphine325IS]

hmm...is it not normal for the RPM to jump at start up slightly?

When I start my 325 it goes up to about 1500rpm then drops back down immediatly. It's almost as if I'm starting my car with my foot on the gas. I never thought much of it.

[Oxford318]

It's not just after start up, it's continually after it's started and it carries on until it is running at normal temp. The AFM does sound likely though. I'll give it a look.

[gwumpkus]

it sounds like the beginnin o the end of the afm..:)..

thats how mine began...at the onset, it was just this: upon starting, the idling hunted up and down a little before settlign down...gradually it got worse...now, it hunts, and sometimes its so bad, it DIES...:(.. i gotta use the gas to maintain the level at about 1000rmp before it settles into an unsteady idle, fluctuating till throttle opens when i drive off..damned AFM...

good luck though.. i think afm's are cheaper where u're located.. :)..

[Oxford318]

A dirty idle control valve was the problem. Nice and cheap! No expensive AFM needed. I thank my lucky stars.