325i sport running and idling problems!!! HELP!!

[ricey46]

Hey, this has probably been covered like a million times before but a can't find the page....
My 325i sport has started revving problems and idling problems. I was driving allong last night when the power just died, pushing the accelerator but just nothing was there, then a moment or two later it bounced back into life! And also this morning i started it up and it woulden't rev above 1500rpm or so. switched it off for a bit, checked the plugs an stuff and its working fine!!
Any help and or advice would be great guys,
Cheers Paul.

[Wid77]

As you say i would do a search because there are plenty of threads on here from people who have had similar problems.

I have had a few minor running and idling problems with my 325i but nothing like as bad as yours sounds. Mine was due to a faulty blue coolant temperature sensor and a bad connection. I would make sure all the basics are right first such as plugs, leads, rotor arm and make sure there are no air leaks anywhere. Other things to check are the throttle position sensor, idle control valve and ariflow meter. However, i am not a mechanic and there are many other people on here with more knowledge of these engines.

[rickk]

I'd check the throttle position switch first, maybe it's stuck in 'idle-mode'.
Measure it, or as a quick check: If you unplug it it defaults to 'drive-mode', which means the idle will be at 1500 rpm or so but should drive normally.

Also check the 2 relays (hit 'm!) on the side of the engine bay, these are for the fuel pump and power to the DME and frequently cause these kind of intermittend faults. I believe there's a relay in the regular relay box you can swap at least the fuel pump relay with just to check.

Next time it happens: take note of what the gauge cluster does. If it dies too, you're probably looking at a Motronic-related issue (most likely: DME main relay or crankshaft position sensor, in the tranny bellhouse), if it remains alive, it's more likely a fuel problem (most likely: bad pump or relay).

HTH, good luck,
- Rick

[Brianmoooore]

I was going to post my suggestions for this, but rickk has just said it all.

[ricey46]

Cheers Guys thanks for the help!!
Just hope its all ok for the BMWCC meet in scone tomorrow!!
Cheers Paul.