got a turbo 2000 v6 scoob which intermitently has rough idle can be at normal idle 800rpm most of the time then other times it up and down from 800 rpm to 400rpm nearly stalling.it has done it every now and then and i have removed the lamba and cleaned of excess carbon and its been fine again.Tryed cleaning the lamba tonight as it had started to idle poor again and it has not helped at all.

Mods

VF24 turbo
K&N cone filter
walbro
front mount
mapped
full decat

 

Have you tried connecting the black leads together under the steering column, to get error codes?

The MAF sensor is the most likely culprit though.

 

will connecting the black plugs work as cel light has never come on?

 

Its probably worth doing, in case a fault code is still in the ECU's memory, although I think a failing Maf doesnt always trigger the Check Engine light, which is a bit scary!!

 

If you're sure you have never seen the CEL, no, connecting the black plugs probably won't tell you anything - although it's worth trying anyway just on the offchance.

You might be able to learn something by getting the car warmed up - to the point where the fluctuating idle is obvious, switching the engine off, unplugging the MAF sensor and restarting it. The check engine light should remain illuminated - but if the idle has noticeably stabilised, chances are your airflow meter is on its way out and should be replaced ASAP - driving either not at all or on very light throttle until the sensor is replaced.

Don't drive it with the sensor disconnected though. If the idle is still all over the place with the sensor disconnected, chances are your problem is elsewhere - possibly an air leak or sticking/clogged idle speed control valve.

 

i ll try that tomorrow at work then as drove it ths morning been irratic and drove home to night it was completely fine.i have a maf that came with the car but no idea if its good or bad.is there any way of testing it apart from fitting it to the car?

 

took youngster to school this morning and it started playing up.Turned off and disconnected maf ,check engine light came on and idled spot on.turned off and reconnected maf and ran crap again.

Got a maf ordered for tomorrow so will fit it and do a ecu reset and hope to god its fixed.