Fuelling issue when hot ? - help appreciated

[MattH3764]

Starting yesterday, once my car gets up closer to operating temp (when the oil reaches about 80, say) the engine starts to labour when manoevering at low speed. Like I'm not giving it enough throttle, but I am of course.

The car runs fine when cold.

So I am thinking:
- intermittent issue - more liekly to be electrical / sensor related than mechanical
- fuelling is the most logical thing I can come up with.

So I'm keen for other thoughts. And if you agree it may be fuel it could be great to know what sensors and electrical bits might be the culprit:
- I replaced the TPS about 10 months ago with an OEM one, as the car had started to run rough. I could put the old one back.
- Blue sensor in the coolant rail is important, so I could easily change that.
- ECU ? Hope not.
- Other thoughts ?

Thanks a lot in advance.

[Grandadg90]

My initial thoughts were that it could be your maf. Best to get an elecrtical reading across it if you can, or swap over from another car to do a quick test, or it could be a coil. Most liklely your coil would show up on idle, ie idling a bit rough.

[Dave P]

Could you unplug the MAF to see if the problem goes away also worth checking for air leaks?

[MattH3764]

Thanks chaps. Forgot about the MAF but that must be plausible.

Dave - forgive my ignorance but what other side effects would unplugging the MAF have ? I always thought it needed to be plugged in for the ECU to work properly, but that may be wrong ?

[Dave P]

Thanks chaps. Forgot about the MAF but that must be plausible.

Dave - forgive my ignorance but what other side effects would unplugging the MAF have ? I always thought it needed to be plugged in for the ECU to work properly, but that may be wrong ?

I havent tried running with the MAF disconnected but have read you can unplug it to test - not 100% sure though.

some info here on MAF testing,

http://forums.bimmerforums.com/forum...ht=maf+tapping

[Grandadg90]

You can take the maf out and give it a clean with electrical contact cleaner. Just make sure you air dry it first before putting back in.

[kwoffa]

Is the the throttle cable opening the throttles enough?i:e throttle cable...after the choke has gone off??basic i know but worth a check!!

[MattH3764]

thanks guys for all the thoughts. To be honest, I may have completely misdiagnosed it. Last night it was more intermittent and only happened when slipping the clutch - and I felt a vibration. So I am now thinking something mechanical in the clutch or drivetrain, but I'm really confused how that would be intermittent.

I suspect it will go to the shop.

[Grandadg90]

In that case, best to get it on a ramp have it inspected. Could well be a gearbox or engine mount or could be linked to the clutch(clutch plate or even clutch bearing).

Best get it examined. It's all guess work at the moment.

[MattH3764]

Update - now sure it is a clutch release bearing. The intermittent nature of the fault confused me but my indy tells me it is plausible for this to be worse when the car is warm.

So the car will have a new clutch kit fitted, prob a Sachs. Only 60k miles so I'm hopeful it wont need a flywheel.

[Grandadg90]

Well at least you know now what the issue is. Hope all goes well.

[MattH3764]

Sachs clutch now fitted and all is well. Was a tricky job, as many bolts hadnt been touched in 13+ years.

[Spooks]

Sachs clutch now fitted and all is well. Was a tricky job, as many bolts hadnt been touched in 13+ years.

Did you do it yourself?

[MattH3764]

i didnt. sorry to be misleading - i was recounting the experiences of the chap who did.

[Boogar]

My clutch release bearing is becoming excessively noisy and I am wondering if I will have to replace the whole clutch to sort it out. Is there a massive danger of me running the car like this for a while before getting it sorted? Any pointers would be greatly appreciated