Hesitation at low revs, pulling off...why?

[Jamie]

Ive noticed that at ANY time (hot or cold) my car some sometimes hesitates when pulling away from a standing start.

-This has happened on lots of occasion over the span of a few months since owenership - so rules out bringing up crap from fuel line etc/bad fuel etc

-Today the car went bezerk - when turning left into a street, the revs were low and i was trying to pull off but i had NO power, the revs then just kept goin up and down between 500 - 2000 rpm. Car rolled into street and i was like 'heck - whats wrong? ' - turned engine off and then back on again straight away and it was fine, as if nothing ever happened....any ideas?

-Car doesnt need a service for another 3000 miles

-Ive tried a '1 shot dose' of fuel tank/engine fuel addative cleaner - no change

At high revs, cars as smooth as you like

And its only sometimes, othertimes its normal

Ive read up on a few thing like sensors, and some probe or other...

Ive read that you can get ur ECU updated with a newer version if there is one available?

Any ideas/suggestion on what I can try?

Thanks

Jamie

[peppernick]

Can be a lot of things really. MAF, crank position sensor, fuel injector, plugs etc. You will need a diagnostic check by an independent or your dealer.

However, I've heard in the past the 2.0L valtronic do suffer from such problem occasionally but I cannot remember what was the common cause. BigFas will be in a better position to tell you as he had similar problems in the past.

Either way I think a diagnostic check is a good start.

[Ali]

What engine do you have??

If it's a valvetronic 2.0 then its a very common problem!! My 318i ES used to do it so often... really frustrating!

Never managed to get it sorted tho...

[Jamie]

What engine do you have??

If it's a valvetronic 2.0 then its a very common problem!! My 318i ES used to do it so often... really frustrating!

Never managed to get it sorted tho...


Yup valvetronic 2.0

Id luv to go and get a diag check done @ stealers - but i KNOW they will 'find' sumthing (even if there is nothing) and charge me an arm and 2 legs for the pleasure!

[BigFas]

Doesn't sound like a plug, that's what happened to mine, it was spluttering like hell, totally undriveable and the engine management light came on. That's the most common problem.

Sounds like the MAF. If you're handy with the spanner, take apart your airbox and see if there's any muck blocking the sensor, give it a gentle clean, see if that helps.

I'll do some digging around in the morning, see if there's anything else that could be the issue

[Jamie]

Doesn't sound like a plug, that's what happened to mine, it was spluttering like hell, totally undriveable and the engine management light came on. That's the most common problem.

Sounds like the MAF. If you're handy with the spanner, take apart your airbox and see if there's any muck blocking the sensor, give it a gentle clean, see if that helps.

I'll do some digging around in the morning, see if there's anything else that could be the issue

Humm - defo no engine management light comming on.

Oh yea, i also read about water/damp around the coils in the coil pack? Where is this and how do i check it? Could this be related?

As for the MAF - this site AFTER the airbox right? If so i remember i tried to take that apart, only got 2 bolts off - cudnt see anymore and it wudnt budge. Any pics? Ideas?

[BigFas]

Coil pack issue will be the same as the plug issue I've described. The car will be totally undriveable and any issues with the coil pack will invoke the EML to come on.

The valvetronic airbox is an arse to take apart, you just need to be patient. It's hard to describe what to do without actually doing it. The MAF is bolted to the side of the airbox, you need a monkey wrench to grip both sides, squeeze and pull. You'll only need to unbolt the airbox from its mounting points to get access to that area, not other bolts should need undoing

[Matt H330]

THis sounds similar to the problem I have. I know I have a 330i but I have had the MAF changed and it still does it. I suspect the coil packs as this was also a common fault on VW's and with them also there is no EM light and no fault codes. The coil packs breakdown under pressure. I think that 2 of mine are suspect.