Hunting at idle

[march109]

Hello guys

my car is hunting at idle only when warm, assume cold start stops it from happening.

When warm the revs drop and raise over a range of 300-500RPM from about a minimum of 400RPM only when idling, if I then give it some throttle before moving off it threatens to stall and revs drop to almost 0 before flying up again.

I've checked for air leaks and can't find any, but that doesn't mean there arn't any. What really pees me off is that I only fixed the last problem last week and it was spot on for 7 days before something else going!

Forgot to mention it also smells like its running rich when this happens, there is a strong smell of petrol from the exhaust (definatly not engine bay).

What could it be?

[march109]

bump

[ajm-e30]

iv gto the same problem, gonna try n sort it on friday so ill keep u up to speed mate

[Alex]

I have a similar problem with my 316. what engine is yours??

[march109]

325 M20, I had this before and replaced the ICV, it was fixed for 7 days but back to normal now.

But its also running rich too, which is odd!

[ajm-e30]

is the icv round the right way? the other thing to do is clean the throttle body and inlet tract

[march109]

cleaned the throttle body too, ICV is definatly the right way round ran fine for a week.

Now whats the inlet tract? cos I know I haven't cleaned that as I don't know what it is!

[ajm-e30]

int tract is throttle body, black inlet boot, air meter and filter box and filter mate, could also be down to the tps

[march109]

cable into my tps is slack, tried adjusting that too, but can't get it to budge!

how do you adjust it, I tried turning the plastic sheath on the cable up the thread so to speak but it didn't budge and after almost breaking it I gave up for fear of stuffing my dail driver completely!

[E30BeemerLad]

this any help?
http://www.e30zone.net/modules.php?name ... ing+banned

[march109]

No not reall thats another bloody thing it could be!

no seriously thanks everylittle helps as the tv keeps telling me!

[E30BeemerLad]

when it is warmed up leave it running and spray WD40 around the inlet manifold where it bolts to the head, if the idle sorts itself out then there's your problem

[march109]

cheers dude, WD40 made by the gods themselves!

It was once said by a wise old man "if it moves and it shouldn't use gaffa tape, if it doesn't and it should use WD40 !"

Well I have a busy saturday now.

[hairydave]

I think carb cleaner will work better than WD40. Im sure i have read to keep WD40 away from running engines, im sure someone will no if it's safe to use or if im mistaken.

[march109]

lets hope someone lets me know soon, I'm warming the engine to test now!!

where can I get car cleaner? what would you recomend?

[Splod]

Hi

Replacing the flexible hose from the air flow meter to the throttle body made a big difference to the lumpy idle and hesitation on my 320 m20 engine. Also improved the mpg from about 20 to 25. It didnt look bad, but had one or two hairline cracks in it. Part no 13711726204 on mine (1990 car) and cost about £15.00.

But maybe you've replaced this?

Good Luck

Steve W