Faulty MAF sensor - what problems will it cause?

[Mark Elder]

My indy says my MAF (mass air flow) sensor is "not sending any signal". He's pretty good at not emptying your wallet unnecessarily and has said "if you feel a need to change it let me know".

That's great while it's not causing me a problem (and it has not so far) - but this morning (first cold morning of this season) I had problems getting car to start. (well, took 2 attempts, but when it did start it was really weak for a few seconds - was obviously about to stall until it had woken itself up)

Anyone any experience of a faulty MAF and what the symptoms are?

Thanks

 

[jboult]

Mark,

No direct experience on my 993 (touch wood), but had the same issue on a 944 Turbo. Car suddenly stalled on me, then would fire up (eventually) and die again. Tapping the MAF cured it immediately (easy to get to on a 944), but I replaced it anyway as it was obviously on the way out. Not cheap...

Cheers/John

 

[Mark Elder]

I've read somewhere you can clean the MAF (with electrical contact cleaner I seem to remember).

Anyone know the procedure for this (even simple things like "where is the MAF?" might help a non-mechanic like me[8|])

Thanks

 

[Johnny C]

When the MAF isn't working, the system defaults to (IIRC) 5v, which is a default average. It shouldn't stop your car starting, just means it won't run that efficiently once it's going so power may be a bit down and mpg will be a bit high. it shouldn't cause any starting problems though..

Have you had your dizzies checked recently? If they're on their way out they will have been fine during the summer but now that we're starting to get condensation on the morning the fault will manifest itself. Mine weren't showing up as faulty on the system check but popping a set of replacements in cured the fault.

Mine went last year, 9M put a 2nd hand set in, which have been fine.