Pf/L m20b20 idle question

[Jamez 2147483647]

allo allo

so my 320i m20b20 (pf/l) is hunting once hot, aka non stable idle

symptoms go like this

• Cold - Good idle of ~1000
• Warm - Hunting goes from ~1000-1300
• Hot - Hunting in full stride, hunts from ~600-1500

most air pipes are new, idle control valve worked perfectly on old engine(using same one)

will it hunt if timing is out? ive also read that it can be caused by the AFM but the old engine didn't hunt and used the same AFM, also the ECU worked fine on old engine

The twist is, the idle goes up when the oil cap is removed on the old engine the idle would decrease

messing with the idle valve doesn't do much

also engine does not smoke and makes nearly no mechanical noise, and has good power

hope someone can suggest a solution

cheers in advance, James

[*Glenn* 854]

I think you need to buy a E36 Compact

Edited March 6, 2009 by *Glenn*

[Jamez 2147483647]

pffft im saving my penny's for a 325i e30

[e30plz 1]

I think you need to buy a E36 Compact

Very helpful, Haha.

[bravo 34]

Possible vacuum leak. Check all hoses etc around intake manifold and throttle body, esp the large rubber intake boot.

If its not that, at least that'll eliminate that as an option.

Then check fuel. Maybe ICV is supplying the extra you need when its cold, but its leaning out once it warms up and the ICV shuts off.

I'm taking a stab in the dark though.

[Jamez 2147483647]

yeah ive checked all the hoses thrice, im going to get it dyno tuned soon anyway,pretty sure Gavin @ high velocity will sort it out in no time

[joshnz 2]

Let us know what the outcome is, mine has a mean dodgy idle, and continually stalls when downshifting up to traffic lights etc, revs drop, engine dies.