MAF or ECU fault on MY99 U.K Turbo ? A couple of months ago I stopped using optimax and filled up with usual unleaded and did a ECU reset. The car would then not idle. So I changed back to optimax and did another ECU reset, my car still wouldn't idle. The car had been running o.k till I did this, apart from having a very slight missfire/hesitation at 2000-2500 revs. I have since changed the plugs,lambda sensor and cleaned out all breather pipes, ICV and boost solinoid. My car still doesn't idle and the missfire/hessitation at 2000-2500 has got a lot worse.
When I perfom an ECU reset it only takes a few seconds driving for the pulsing cel light to come on (showing no fault). This doesn't seem right.
I think there may be a fault on the ECU (AE800), or can a faulty MAf cause the ECU to do this, along with the other symtoms ?
Thanks, Gray

 

Hi, The Ecu sometimes doesnt pick up a faulty maf even when its totally gone. I know a few people this has happened to and putting a new Maf in fixed it.

A new Maf is £80 and Im pretty sure it will sort your problem out.

 

Thanks for the reply Racey Jase. Could a faulty MAF cause the ECU to reset so quickly, like I said, when I do a ECU reset the pulsing cel light comes on in seconds rather than minutes.

 

Dont wanna hyjack your thread m8 but ive read on here that you should treat your MAF as a service item,Over what period of time should you change it and how do you know if its failing?.I have read on here that you can unplug the sensor with the engine running,Ive tryed this and all that happened is that the tickover fluctuated alittle for a couple of secs but then smoothed out.My Car is an MY99 UK torbo and i changed the MAF about 18 months ago cos it was deffo fubar.

 

My cel light comes on quite quick too when resetting the ECU so I think thats normal so I wouldnt worry.

Im from www.RB5oc.co.uk where all our cars are the `99 model. If you need any further advise or a second opinion just register for free on there as the guys are friendly enough and will try to help.

 

If after removing the plug to the MAF sensor your idle improves it is more than likely fubar

 

I agree, if you unplug the MAF it should stall. It sounds like R5 GTT Steve's is deffo faulty. Mine does stall the car when unplugged, but still seems to be faulty.