Thread: How well is your MAF performing?

Checked mine with Nissan Data Scan, 1.49v-1.50 at idle.

Follow Scotty's directions above to add the MAF low voltage enrichment value to your XDF file so that you can see this parameter when you load a bin file into TunerPro.

Once you have saved your XDF file, load a bin and open the Low MAF Voltage Enrichment field. If you set this lower than whatever your MAF is reading at idle, it should alleviate drivability problems associated with low MAF voltage.

I would consider this to be a temporary solution while sourcing a replacement MAF.

BTW, the 1993 FSM shows the range of MAF voltages at idle to be 1.3-1.7v. A MAF showing values less than this should be replaced according to the FSM.

Scotty works on B13s mostly so I'm guessing that his XDF directions apply to B13s, not B14s, but I'm not sure.

You're welcome. Just happened across these strange findings while troubleshooting. Most people just assume the MAFs are fine & perform the Grounding Mod as the only check. Well, I have discovered differently. Although the ground mod really helps to improve the MAF signal, some MAFs are still much too weak to perform within specs. And I was also guilty of overlooking this possiblity when tracking down multiple idle issues & moving on to other culprits like the IACV & Air Regulator.

This is just another thing to check when testing/troubleshoot our cars.




Agreed... But to perform this test accurately:

You MUST perform the test with the car idling AND at operating temperature.

From my experience, Testing with the engine off will not produce a dependable MAF signal and it is usually very low. With the car running, the MAF signal is at it strongest.



See my comment below to Bill.



Thats a very good signal Vad.. You can safely assume that your MAF is strong and that your issues are caused by something else..



Thanks Bill.. You are correct.. Ive mainly tested this with B13 cars; as I own a B13..
But this also applies to B14 cars and I validated this yesterday on a B14 ODB2 car.
For the B14, I had to change B14 XDF file to use the "E" address prefix: EA22 (instead of 0A22 for B13s)

Yep and the good ones usually reads in the 1.3 - 1.5v range. I havent seen one above 1.5v yet, out of the maybe 15 or so tested thusfar.. Also, I agree that this is only a temporary solution for weaker MAFs while sourcing a replacement.

I think I got an intake pipe leak or bov line leak. Not too worried, replacing most of the piping in the next few weeks

EDIT: I just looked over my logs from driving yesterday and in neutral, Air Flow is at 1.14.... at 4v TPS (6,362 RPM), the Air Flow is at 4.56.

Vad.. Take a real reading on the MAF with a DVM at idle. Using datascan is nice and shows what the ECU is seeing but taking a real reading with a DVM is probably more accurate.. 1.14v MAF reading is borderline at idle and indicates a MAF getting tired..

I'm ditching all the current solder wiring and will crimp/heat shrink it tonight.

To everyone that yelled at me using crimps instead of solder, for the last time solder does not belong in the engine bay!!!

Agree with you Vadium.. Solder should only be used inside the car and NOT in the engine bay. Heat and vibrations causes solder to crackup over time..

But lets stay on subject here.. MAF Performance...

Yes, of course, I'll be posting up my results tonight after I get some new connections in. I think I will grab a can of maf cleaner and see how it does too

Redid my connects for the MAF, still at 1.10 at idle... looks like I might be needing to do your BIN file trick...

Okay, here is the HowTo Perform the MAF voltage test .

Heres the JWT MAF wiring info.. Just find your MAF in the list to identify your "Signal to ECU" wire.
The MAF Signal wire color is listed in the "0-5V SIGNAL OUT" column in the table. (The Z32 MAF wiring is in the top diagram).

Then do the following with engine running at operating temps.
1. Insert a straightened paper clip into the hole with the Signal wire on the harness side of MAF plug (while plugged into MAF & Engine running).
2. Connect the Positive DVM lead to the paper clip (using alligator clips).
3. Connect the Negative DVM lead (using alligator clips) to the Intake Mani grounding screws (NOT the battery ground).
4. Turn the DVM to VOLTAGE with 2 decimal points.

You will now have the MAF Signal value at idle. Hopefully its between 1.5v & 2.0v... If not, find another MAF!!