Rough Idle

[Jazmac]

Hi all, some ideas/help needed!

as per topic title when i start the car its rather lumpy, when heated and stopping at lights etc it idles rather lumpy, however during driving it seems ok but i do get what i can best describe as pulses or jerks, like the car is wanting to go faster like little power kicks even though im driving at a constant speed fell it more on the m-way sitting about 60-70mph.

Checked the coil pack and electrical spark by removing 1 lead at a time never made any difference to engine running when removed or not, sparkies were replaced approx 2 months ago with standard spec, but not checked them since to see if any unusual signs. Air filter checked and cleaned yesterday(K&N type) and checked ecu for falt codes using onboard black plugs under steering colum with a result of no fault codes present

Oh and its a 99 S-reg wagon turbo 2000 with approx 89k, all belts replaced, with oil and filter done at same time of plugs.

cheers all

[jae]

I would say either MAF is on it's way out or the idle control valve or at the outside the O2 labda sensor.... most likey culprit I would say is MAF....

the surges at around 3k revs I get all the time and was told it's a quirk of the software/ecu of the 99 model....

[tucku34bt]

I would say either MAF is on it's way out or the idle control valve or at the outside the O2 labda sensor.... most likey culprit I would say is MAF....

the surges at around 3k revs I get all the time and was told it's a quirk of the software/ecu of the 99 model....

i would agree. i had the same problem, replaced the MAF sensor and now its fixed. if you do a search for this type of topic at the bottom of the main page you will find loads of advice as it is a very common fault.