Thread: How well is your MAF performing?

This thread was created with highlights from this thread.

Our old MAFs are not all created or performing equally. They do wear out & some are already almost or completely shot.

I have found that many MAF have seen their better days and are losing their luster & signal strength..
Recently, I have been testing a few MAFs: OEM DE, N60, & E60/61. Its amazing the differences found among these 10-15+ year old MAFs.

Tested several and found the signal strength to vary as much as 1.5v @ idle. Thats approx 1/3 of the max MAF voltage of 5 volts.. I found some MAFs reading @ .22 & .072v!! The normal MAF idle voltage is between 1.5 v & 2.0v at operating temp.

Old weak MAFs can cause weird idle problems & strange hesitation issues. If your car is having these problems, you can test your MAFs to identify its signal condition. Its easy, just test the MAF signal @ idle with the positive connector your grounded DVM set on the voltage setting. The weak ones will be very obvious with their low readings (usually under 1v) & compared to a good MAF will have a noticeable stumbling idle difference.

I have discussed this with Calum on several occasions. Lots of performance issues, poor fuel mpg, and hestitation issues are probably being caused by worn-out MAFs.

The idle MAF voltage must be greater than the Low MAF Voltage Enrichment Trigger constant in your ecu bin file.
Otherwise wierd idle/performance issues can occur..
Normal Calums bins has this constant set at 1.0v and Jim Wolfe bins has the constant set at 0.0v or 0.01v.
So Im thinking that the MAF should read at least 1v just to be safe..

Calum provided this info to manually add this constant to the xdf,
Create the following:

-constant/scalar
-address 0A22 or EA22
-size 16 bits
-units of Volts
-conversion formula of 'X * .005'
-title: EA22 - Low MAF Voltage Enrichment Trigger

Then save your XDF..

Thought I would post this information & to see if other members have experimented with this.
Also posted this to inform members of our old & tired MAFs..
Also be aware that many Junkyard MAFs are also old & weak...

Update:
Found this link on the old forum with similar info..
It is looking at the MAF causing idle/stall dive issues b/c the MAF/Filter is placed in a
turbulent location (fender well). Who knew??

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!!

FYI guys not all MAF's have the same voltages at idle. I spent about two hours messing with the two E60 MAF's, on the phone with Scotty getting advice, checking for intake leaks, to still have 1.09 idle volts with my E60 MAF.

This morning I looked up the 1997 Maxima FSM and saw something very interesting.




So what this means is, every MAF is not going to have the same voltages at idle. Below is a list of MAF's and FSM's that I looked through and found information about.

MAF: DE
Car: 1991-1999 Sentra
Idle Voltage: 1.3-1.7v

MAF: E60
Car: 1995-1999 Maxima
Idle Voltage: 1.0-1.7

MAF: N60
Car: 1991-1994 Maxima
Idle Voltage:1.0-1.7 (assuming it's similar to N62)

MAF: N62
Car: 1990-1996 300zx
Idle Voltage: 1.0-1.7

MAF: RR
Car: 2000-2001 Sentra SE, 2000-2002 G20
Idle Voltage: 1.3-1.7v

Agreed Vadium. V6/V8 idle at much lower rates. My Q45 idles smoothly between 500-600 RPM.
But these older 4 bangers requires a much higher idle (especially when boosted or with cams).

MAF Discoveries

1. The Low MAF Voltage Enrichment Trigger constant must be lower than the MAF minimum voltage... Period... Setting the Trigger to .7 should be safe and the Nissan MAFs are all at least 1.0v or higher.

2. Also, we also found that the MAF should not have turbulant air as this causes MAF voltages to jump around (both above & below 1.0v). Setting the Trigger to .7 will also correct this problem.

3. Any Nissan MAF running below 1.0v at idle should be considered out-of-spec (useful life has ended) and should be replaced.

These rules have been found critical for a smooth non-hunting idle & to help remove hesitation caused by the ECU attempting MAF corrections.