1990 325i running rough

[PC]

I've had this problem with the car for 2 years or so. It's a 90k FSH excellent condition convertible, but it runs rough which really spoils it. It's hesitant when pulling away from a standstill and can throw you around the car at 1500 revs particularly when cold. At a steady 2300-2500 revs it runs pretty rough too.

I've tried the airflow meter, coil, leads and I'm sure I've tried more. It's been to a Bosch place for a couple weeks and they didn't find the problem, although they commented that the fuel pipes are looking worn. Could it just be the fuel pipes? 2 other opinions I got are that the fuel pipes are OK. Any other ideas from anyone, or any recommendations for a place I could take the car in Edinburgh/Scotland?

I had a similar problem on a Cavalier SRi many years ago and it was an air leak in a duct between the airflow meter and the engine (I've also had this suggested to my from another site), but wouldn't the diagnostics pick this up?

I was thinking of replacing the fuel pipes anyway and considering taking the car to BMW, but I don't really want to keep throwing money at diagnostic checks without any results!!

I'd be grateful for any suggestions

Thanks
PC

[dsio]

Your ECU ok? If you flatten or disconnect the battery on those engines, it should run alot rougher than usual and almost stall at idle for a period of time (1 hourish from memory) until the ECU relearns everything.

Have you been doing electronic work on it, causing power distruption? and if you take the negative off for 5 mins or so and then drive the car, does it seam worse, or the same?

[E30BeemerLad]

just a quick way of seeing if it could be the inlet manifold gasket is to start the car and let it warm up so it's up to running temp and then spray wd40 around the inlet manifold where it bolts to the side of the head.if normal idle is resumed then that tells you inlet manifold gasket is on the fritz.

My car suddenly developed a lumpy idle and would jerk like fcuk when pulling away with very small throttle openings or when driving along in heavy traffic with a constant light throttle opening.

You didn't mention a problem with the idle so I may be off the mark here

[sabrje]

Welcome to the zone - you're sure to get plenty of advice here.

Its probably worth replacing the flexiblefuel hoses anyway as they only cost a few quid and tend to perish anyway. I'd visually check the rubber belows between the AFM and the engine as these are known to split as well. Check the breather hose and rocker cover gasket as well. This is because the pressure above the head is important - just try running the car without the oil filler cap!! This is just the cheap and easy stuff. You might also have a problem with the engine temperature sensors.

I'm sure someone else will come up with other ideas - good luck.

[PC]

Thanks all

I had two E30's til recently and I know the issue with the car not running right after a flat battery, but that doesn't seem to affect this one. My other one was dreadful for 10-20 miles, but this one tends to work fine.

Idle is OK although it did have sticking idle valve previously which was causing it to cut out at idle. That cleaned up and sorted that issue out

I'm going to have a close look for cracks causing an air leak

Thanks for the suggestions so far, please keep them coming!

PC

[Simon13]

i have a similar prob at the moment but not as severe, i have a new pipe from the airbox to throttle body as when i cleaned the ICV i noticed tine cracks in the rubber. Ԛ£14 it is so worth a try!