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View Full Version : IDLE PROBLEM, please help!!



liljos
08-31-2011, 11:23 PM
ill add pictures if requested*my e34 (m20) has an idle problem and misfire. the car was running great till about this week. last week it wasn't running due to a slave cylinder failure. I replaced that and got the clutch working. at first the car wouldn't start and after having a BMW specialist diagnose it and removing/testing the fuel pump, he swapped the fuel relay with another similar(blue) relay under the hood. the specialist told me I had a bad fp relay. after the car got started, it idled fine. but then it would jump to 2k or 2500 and just stay there. *when the idle goes back to normal (700-900) the check engine light comes on. when the revs increase, the check engine light goes off. when driving; it takes off from 1st pretty rough and jumps. in any other gear if I go wide open throttle it stutters, especially in 5th. sometimes it will even completely just shut down.*what I think: I'm not looking at any vacuum leaks but there are a few things I'll point out. there are 2 in/outlets (not sure) that are to the left of the tb. they look like they would have hoses attached to them but don't have any.*when the tech was working on my car and the idle climbed, he tapped on the ICV and it started to idle normal.*my car tells me: the oil level sensor*there are 2 plugs. one on each side with orange housing that I can't seem to find where they go or are for.*there's a plug right above the alternator that isn't connected?(possible oil level sensor?)*I'm trying to get help and figure out the idle problem and why it randomly shut down.*and I also recently discovered my car has Bosch platinum 4+ spark plugs.*

genphreak
09-01-2011, 07:22 AM
Those plugs can be a problem.

ICV will need a clean as it an cause all sorts of drivability trouble as you describe.

Not looking for leaks? IMH experience, one looks for vacuum leaks long and hard, or spends a long time working on non trivial, non root cause issues

Use a fuel pressure gauge to check you have 43.5 PSI.

Stick the car on diagnostics to 'know what it thinks of itself'. Those plugs could be causing lots of weirdness... but the old vacuum pipes connectors and even sensors are the most likely trouble. Check the oil level connector is properly connected but this is a common fault nothing to do with drivability.

liljos
09-02-2011, 12:20 PM
where could the possible vacuum leaks be? and i think the problem is fuel delivery. i removed my fuel pump a week ago and ran it on a bettery, it seemed to run fine. but once it's back in the car and it's cranking, it makes some weird sounds as it's running. it sounds as if it's running kind of rough and when i stop cranking it, it cuts off pretty rough. possible fuel pump replacement?

genphreak
09-03-2011, 09:20 AM
Sure. Try running it manually (ensure **zero** risk of sparking contacts mind you!) and turning on/off. Did you check the FPR- manifold line btw?

ahlem
09-08-2011, 07:44 PM
Your fuel pump may run and deliver fuel as observed but unless you get the right psi you will have problems as you described.