Its a Renault Megane (2000 so old style), and car is abroad at the moment so I'm trying to help over the phone!

basically, quite frequently the revs will raise at idle to about 1100rpm (from 700ish) and run very lumpy.
Also when driving, often the car loses a lot of power, again feels lumpy and doesnt really accelerate at all, then all of a sudden it will cure and lurch forward.

happens when engine is hot or cold, but seems a bit better when warmer.

To me this sounds like its running on 3?

Are there any other quick things people can suggest to check? Im getting more details later but for now thats the obvious cause?
No engine management light on either if that helps
Cheers all

 

sounds like it could be a fuelling fault. (if its not a spark fault - ie running on 3)

check the lambda sensor as these often fail

 

cheers will try and get the message over, im hoping its not a sensor fault and its something easy to fix up temporary!

 

Could also be EGR or a coil (if runnin seperate coils) as they're reknown for them breaking down ! ! !

Good luck !

Jb

 

Cheers Jb, just been trawling the renault forums, you're quite right, looks like its most likely coil dying, hopefully it wont take out the cat before it gets back to the UK

 

they run AFMs? sounds like fucked/disconnected AFM too.

 

I'd agree with this guy, they're well known for it.