MAF Voltage Readings.

PonyGTrider

Active Member
Feb 27, 2019
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Hi there,
In my 90 GT twisted wedge, TFS intakes, TFS-1 cam, 19lb injectors, 65mm TB, and Cold Air Intake, I have a 70mm MAF tube and F2VF-12B579-AA sensor out of a 95 V6.
What do you think about those readings? They kind of look weird to me…

Idle - 0.951 Volts
20 mph - 1.935 Volts
40 mph - 0.179 Volts
60 mph - 1.904 volts

I know the stock MAF set up supposed to have:

Idle - 0.60 Volts
20 mph - 1.10 Volts
40 mph - 1.70 Volts
60 mph - 2.10 Volts

What the readings supposed to be on that 70mm MAF????

Would you agree that maybe that F2VF sensor is bad? And if that’s the case what would be the symptoms??? Perhaps higher fuel consumption or what else?

Anyone running that same MAF tube and sensor that had taken those measurements and if you can share them would be great!

Engine runs good I guess and idles good but I still have bad MPG, something like 9 -10 mpg and believe me I don’t have a lead foot.

Thanks for helping me on this one
 
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Hi there,
In my 90 GT twisted wedge, TFS intakes, TFS-1 cam, 19lb injectors, 65mm TB, and Cold Air Intake, I have a 70mm MAF tube and F2VF-12B579-AA sensor out of a 95 V6.
What do you think about those readings? They kind of look weird to me…

Idle - 0.951 Volts
20 mph - 1.935 Volts
40 mph - 0.179 Volts
60 mph - 1.904 volts

I know the stock MAF set up supposed to have:

Idle - 0.60 Volts
20 mph - 1.10 Volts
40 mph - 1.70 Volts
60 mph - 2.10 Volts

What the readings supposed to be on that 70mm MAF????

Would you agree that maybe that F2VF sensor is bad? And if that’s the case what would be the symptoms??? Perhaps higher fuel consumption or what else?

Anyone running that same MAF tube and sensor that had taken those measurements and if you can share them would be great!

Engine runs good I guess and idles good but I still have bad MPG, something like 9 -10 mpg and believe me I don’t have a lead foot.

Thanks for helping me on this one
… By the way, NO ERROR CODES in case someone wondering.
I’ll read you with great interest
 
I think measuring voltage against MPH is very arbitrary.

That said, a larger MAF is going to sample a smaller quantity of air inside of a larger opening. If the tune is not doing the math then the meter will have need to be scaled so that the appropriate amount of fuel is given for the sampled volume of air.

So, it stands to reason that voltage outputs are higher because the meter is sampling a smaller quantity of air and compensating for a larger overall mass of air (because the housing is larger).

So the number you listed appear to scale in the correct direction.

This line however, looks like an anomaly. It should be between those two other values:

40 mph - 0.179 Volts
 
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I think measuring voltage against MPH is very arbitrary.

That said, a larger MAF is going to sample a smaller quantity of air inside of a larger opening. If the tune is not doing the math then the meter will have need to be scaled so that the appropriate amount of fuel is given for the sampled volume of air.

So, it stands to reason that voltage outputs are higher because the meter is sampling a smaller quantity of air and compensating for a larger overall mass of air (because the housing is larger).

So the number you listed appear to scale in the correct direction.

This line however, looks like an anomaly. It should be between those two other values:
Understood, but as a comparison the two sets of voltage look so weird to me. The stock MAF the reading looks linear. More speed more volts. In the 70mm MAF does not show linearity at all the only numbers that make some sense are the Idle and 20mph, the 40mph reading supposed to be higher than the the 20mph and the 60 mph voltage supposed to be higher than the 40mph voltage. It is definitely contrary to the logic stated on the stock MAF setup.

I’ll do the measurements again insure repeatability.

Are this “faulty” readings related to too high fuel consumption???

Then what to do next?
Thank you all for the help
 
Bigger heads... Bigger flow, even at idle...

I just recently tested voltage between a pro-m and a stock MAF (19lb injs) both read EXACTLY the same at idle at 1.02-1.1v
 
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Hi all,
I'm just trying to alive this thread.
I was runing a test on 94-95 Mustang GT 70mm MAF. The readings don't seem normal to me if someone could give an opinion; I measure the voltage between pins C and D standing still and this is what I got:
IDLE speed 0.920 Volts DC
1,500 rpm 1.135 Volts DC
2,500 rpm 1.475 Volts DC

According to another forum the voltage at those rpm's supossed to be:
IDLE speed 0.9 - 1.0 Volts DC
1,500 rpm 1.4 Volts DC
2,500 rpm 1.8 Volts DC

Any thoughts, please?
 
Hi all,
I'm just trying to alive this thread.
I was runing a test on 94-95 Mustang GT 70mm MAF. The readings don't seem normal to me if someone could give an opinion; I measure the voltage between pins C and D standing still and this is what I got:
IDLE speed 0.920 Volts DC
1,500 rpm 1.135 Volts DC
2,500 rpm 1.475 Volts DC

According to another forum the voltage at those rpm's supossed to be:
IDLE speed 0.9 - 1.0 Volts DC
1,500 rpm 1.4 Volts DC
2,500 rpm 1.8 Volts DC

Any thoughts, please?
So your first set of readings are the 70mm MAF, what MAF is the second set - stock?

Your injectors, are they the OEM '90 injectors? If so, have they been cleaned?
 
Hi all,
I'm just trying to alive this thread.
I was runing a test on 94-95 Mustang GT 70mm MAF. The readings don't seem normal to me if someone could give an opinion; I measure the voltage between pins C and D standing still and this is what I got:
IDLE speed 0.920 Volts DC
1,500 rpm 1.135 Volts DC
2,500 rpm 1.475 Volts DC

According to another forum the voltage at those rpm's supossed to be:
IDLE speed 0.9 - 1.0 Volts DC
1,500 rpm 1.4 Volts DC
2,500 rpm 1.8 Volts DC

Any thoughts, please?


I run the same MAF but don't have readings at this time. If i can think of it i can take some at some point. How are you measuring?
 
See #7 here:
 
So your first set of readings are the 70mm MAF, what MAF is the second set - stock?

Your injectors, are they the OEM '90 injectors? If so, have they been cleaned?
Yes first readings are from the 70mm MAF the second redings are from the 55mm MAF. I just serviced the injectors and ther are in perfect conditions. This comparisson of readings are intended to findout if it has anything to do with my poor Miles Per Gallon issue
 
Last edited:
Here's some published data

1714501115283.png
1714501243642.png


Got it from here.

 
Thank you, I’m not sure how (If there is a way) to calculate or translate my figures to find a flow rate…

I think the main take-away is that it's not going to be similar readings. ALso, it's one data point and i'm not sure of their source of the data, so take it with a grain of salt.


Kinda one of those times you wish EEC-IV could output the same sort of data OBD2 can, so you can look at things like fuel trims and o2 sensor voltage swings.

Swap your stock MAF in. You'll lose a bit of power but you can see if you notice any significant difference in fuel economy.