beensoldaduffscooby

Finally found the problem that has been causing overboosting/hesitant acceleration/lean mixture to be a failing MAF sensor.

When I swapped it for a borrowed one everything was cured. I then tried to clean my own as this has reportedly cured some peoples faults. When I replaced it the car would start but only run for about 10 seconds before cutting out. It will restart and run for another 10 seconds then die again. There is no CEL. If I disconect the MAF sensor the car starts and is drivable - so long as you don't use very much throttle. There is obviously a CEL with the sensor disconected.
I will order a new MAF first thing Monday but wondered if it will be ok (ie will not damage anything) if I drive the car very stadilly till I can get the new MAF.
As I understand it the ECU uses the lambda sensor for light acceleraction/cruising and the MAF for heavier use of the right pedal.

TIA Steve.

Brun

Don't know the answer to this but there ain't no way i would use it if it was mine

scooby-zeus28

i just cleaned mine dident work looks like a new 1

ALi-B

iTrader: (1)

Depends on the model year. I know from running my own (MY97) without one (the connector came off) That off boost running is generally ok.

But as soon as you use any boost I got kangaroo impressions and fuel cut.

So on that yes, you can use it, it will run and drive on minimal throttle and revs. But I wouldn't advise it.

Ray_li

where and how do i clean the MAF?
BTW MY00

jjones

don't ray

the my99/00 maf is notoriously dodgy. there is no surefire way (DIY anyhow) of knowing if it is knackered. there are various tests but whether they are foolproof is very doubtful. the only way to be sure is to buy a new one from a dealer at £77 inc vat.

Ray_li

stuff that idea then.

Thanks JJ

Gaz P

Not an expert on Scooby's but I wouldn't advise driving the car with out a fully functioning MAF. It could be over or under fueling like crazy......not good..

StickyMicky

should be running in limp home mode tho shouldnt it??

RB5_245

I had to run mine for a good few miles with no maf once apon a time, off boost it ran rich. If you went on boost by mistake it tried it's hardest to empty the contents of the fuel tank into the engine MY99.

So it will do the cat's no favours. Only drive if there's no alternative I'd say.

Dave

Dyney

Steve,
I had exactly the same problem this morning.

The car would only idle for 10 secs and then died!
I could keep it going if I blip the throtle just before it died.

Turned out it was unmetered air getting in, bypassing the MAF.

I believe the ECU runs off a preset map for the first 10 secs after start up to allow air flow through the MAF to stabalise before it switches to it for info

It sounds like your MAF sensor is totaly fecked or you have an air leak (split hose). I wouldn't drive it unless you absolutely have too untill it is sorted!!!

beensoldaduffscooby

Fitted a new MAF sensor today and all is fixed.

The rough tickover - fixed.
The occasional overboost - fixed.
The VERY lean AFR on guage - fixed.
The next time (and I just know there will be a next time) I have any engine related problems I know which sensor I am changing first.


Thanks to everybody on this and other threads who have offered advice on this problem.

Steve.

Richard Askew

I ran mine without a MAF on standard ECU for 600 miles til yesterday when I had the GEMS fitted and mapped

Quite scarey not being to accelerate through 4000 rpm in top