Fat Freddy wrote:Also what margin would you allow, =/- 0.1V ?
Yes the margin is +-0,1V.
Valhalla wrote:Hi FF,
I think that it would be almost impossible to predict what airflow a MAF is reading (digital or analogue) without (as Tode says) having an extensive library of signal conversion files, and therefore it would be difficult to say "chicken or egg" from the operation of the engine over a speed and load range.
For diesel engines that can calculate the theoretical air mass with simple programs, where enter rpm, manifold pressure and engine capacity, the result is compared with the reading with diagnostic, clearly the value is with egr closed.
If diagnosed I observe that egr is OFF and air mass too low (compared to the theoretical value), I perform the first test MAF then control circuit air / EGR.
For gasoline is more complicated to calculate the theoretical air mass because there is throttle valve, but the test is the same for the MAF and if the sensor is OK and Short / Long term fuel are off the scale, the problem is elsewhere.
Only database, in my opinion, is only for the various models of MAF voltage/frequency departure and voltage/frequency maximum, in the car park there are few models.