BMW M5 Forum and M6 Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
517 Posts
Discussion Starter · #1 ·
I know, I know - another MAF thread! Sorry guys. Just wanted to get a few quick opinions on how bad it is to be outside the voltage specs given in the FAQ thread for testing out MAFs.

After following the voltage test procedure, I see 1.014V from ground to signal and 5.05V referenced to DME on Pass side MAF. Driver's side shows 1.043V and 5.05. Based on the spec, the Pass side is okay and the driver's is a little over the limit.

I got about 140 L/Hr corrected in 3rd gear yesterday. So perhaps my MAFs are not too far off after all? What have you guys typically seen for voltage measurements when you know your MAFs are really bad (giving very low L/Hr readings)?

thx
Sean Paul
 

·
Registered
Joined
·
12,398 Posts
I'm of the opinion that voltage readings are useless for evaluating the QUALITY of the MAF.... Yes, it can ID a dead maf.... but as a maf fouls what changes is the linearity or calibration. So unless you can measure the voltage at say 300 cubic feet per minute, you will not be able to measure this degradation.

IMO
 

·
Registered
Joined
·
517 Posts
Discussion Starter · #4 ·
Thanks for the opinions, guys! Guess I thought those voltage measurements were a very firm indicator on their own.

I'll make a WOT run in 2nd gear and see what flow it posts. Beast seems to be running pretty well, no major concerns in this department.

the MAFs definitely have not been changed in the 40k since I've owned it and I have nooo idea when the previous owner may have done it. There is some good documentation with the car but none indicating MAFs. 135k miles on original MAFs? :eek7:

SP
 
1 - 5 of 5 Posts
Top