ACCELR8

Well, I accidentally connected my MAFT wrong and drove the car for approximately 50 miles before I realized it. Once I realized it, I looked at the MAFT owner's manual and it said connecting the MAFT incorrectly can ruin your MAF sensor. How can you tell if your MAF sensor is bad? Are there any variables in Autotap that can be monitored and will indicate if the MAF sensor is bad?

Thanks,

Jim

jimmyblue

iTrader: (11)

Start with MAF output frequency, raw; should be
about 2500Hz on an automatic, probably more like
1500-2000 for a manual with light accessory load,
at warm idle.

If you see that, it's alive and probably unhurt.

Under 1500Hz or much above 3000Hz would be
abnormal (as would lack of output entirely).

ACCELR8

Thank you!

ACCELR8

I just collected some data:

at idle the MAF frequency is around 2500
at normal driving (approximately 8% throttle and less than 2000 RPM) the MAF frequency is around 3600
at WOT the MAF frequency is around 9000

In addition, ever since I installed the MAFT incorrectly the timing won't go above 22 degrees at WOT (with no knock retard). Prior to this the timing was around 27 degrees at WOT.

The car is a M6. Does any of this information indicate that the MAF sensor is bad?

Thanks,

Jim

jimmyblue

iTrader: (11)

These appear pretty normal. WOT output on
mine runs up right to about 10,000Hz (6100RPM
peak RPM from 6000RPM shiftpoint A4; if you
short shift it a little 9000 is not unreasonable).

MAF messing-around will alter timing. If you set
MAFT for lean then it will advance timing. I run
29-30 WOT at high RPM (Predator at first, then
HPTuners). 22 seems like about where the stock
would be if you didn't have something altering it.
Was 27 with, or without the MAF?

MAF faults might have defaulted you to the low
octane table too, which might have to learn its
way back out. But this is only conjecture on my
part.

ls1pepito

What do yall guys use to check your frequencies ?

HumpinSS

iTrader: (1)

Efilive, autotap and I am not sure about HPTUners

ACCELR8

The 27 degrees timing was without the MAFT. I thought I read somewhere that 22 degrees timing at WOT is normal for '01-'02 cars and 29 degrees is normal for '00 and older cars.

Anyways, I'm glad the frequencies seem reasonable. I'll have to do some more research to resolve my timing issues.

Thanks for your help jimmyblue!

ACCELR8

FYI - I didn't do anything to the car and the timing is back up to around 26 degrees at WOT. I'm guessing the computer retarded the timing when I installed the MAFT incorrectly. Now that the MAFT is removed the computer had to re-learn and it just took awhile for the timing to get back to normal. - just a guess.