Maf

[bowen]

Ok,

I am still getting a rough/misfire idle at cold start. I unplugged the maf last night, the engine was already warm and took the car out (i think) it pulled better however I got a huge hesitation at full boost.

This mornings cold start with no MAF was fine, smooth idle and power seems great.

The only thing is the MAF is new 5 months old if that? Does anyone have a pic of the MAF fitted, I am not sure if I installed it back to front?

Cheers,

 

[demus]

Is it an oil burner or petrol? It has been known on other forums that some MAFs are not the genuine article, where did you get yours from?
If its happier with it disconnected then it probably is failing, the output normally drops as they fail, making the ECU inject less fuel due to it thinking the airflow is lower, that would cause a rough idle at cold because it will be too lean, is it better when its warm?
That said when they do fail they normally still start ok when cold...

 

[bowen]

Hi Mark,

Its a 1.8t.

With the MAF plugged in I get a misfire or rough cold start, on boost it hesitates and jerks.

Without MAF, i still get a rough idle from cold. On boost it pulls harder, but still get a hesitation on full boost?

 

[demus]

Hard to say if it is the MAF in that case, have you had it scanned for any faults?

Maybe coilpacks or plugs...

 

[brasiliangringo]

You cant diagnose it efficiently unless you have access to VCDS to run some checks. A good MAF at peak RPMs is making around 80% of max BHP, so a 200bhp car shld have a healthy MAF peak at around 160 g/s.

 

[bowen]

Thanks both, getting new plugs fitted next week and lgging with vcds too!

 

[demus]

Have you checked the intake hoses for splits etc, both sides of the turbo...any air leaks anywhere??

 

[bowen]

do you mean the turbo intake pipe? If so yes, with nothing looking out of place.

I stripped down the air box, checked for leaks and all vac hoses and nothing!

 

[JamesV]

hi mate, just wondering if you have sorted your problem? I have the car issue with mine and wondering which direction to go in, I got mine scanned earlier and came back with this code:

17544 P1136 001
Bank1, mixture adaption (add)
System too lean
Static