Mass Air Meter 91 Mustang

bman91gt

Member
Nov 13, 2015
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virginia
Question currently I have a pro m 75 mm mass air meter and I have a slight miss hesitation at low rpms.im wondering if this problem could be my mass air meter cause I have been reading up on the mass air meters and to me it makes sense. And I can see a lot of people seem to have this problem with aftermarket meters. Currently thinking about a 94-95 gt or cobra mass air meter because it's a little bigger. But also just thinking of getting a mass air sensor and putting it in my old c&l 76mm housing cause it ran fine with that setup, but I also hear a lot of bad things about c& l meters also. And one more thing anyone ever use a mass air meter,sensor from advance auto or auto zone or Oreily how do they perform. So opinions what do you guys like to run. any help is appreciated .
 
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Ok so it ran fine with a c&l? Then who cares what people say about them if it ran fine before?
I actually recently swapped to a pro m 75 myself and had driveability issues. Threw my old c&l back in and now no problems, go figure.
 
Ok so it ran fine with a c&l? Then who cares what people say about them if it ran fine before?
I actually recently swapped to a pro m 75 myself and had driveability issues. Threw my old c&l back in and now no problems, go figure.

Well just trying to make an informed decision this time around I thought the Pro M was the way to go, but apparently I was mistaken.the old sensor in my C&L unit went bad so I just got a pro m without doing any research. So now I'm debating over the stock 94-95 gt meter or just buying a sensor for my old C&L, but I'm also not sure about the parts stores sensors either
 
I have heard lots of bad things about c&l just like you but i have been running one in my setup for a long time now. I thought i would upgrade since i had ordered an Anderson power pipe .
I couldnt believe how bad the car ran with the pro m meter installed on it!

The guys around here i believe like the 94 95 mass air meters, at least thats what i have found reading through some of these threads.
 
I have heard lots of bad things about c&l just like you but i have been running one in my setup for a long time now. I thought i would upgrade since i had ordered an Anderson power pipe .
I couldnt believe how bad the car ran with the pro m meter installed on it!

The guys around here i believe like the 94 95 mass air meters, at least thats what i have found reading through some of these threads.

Thanks for sharing your experiences with both C&L and pro m meters, if you don't mind me asking what kind of setup are you running, do you have H,C,I. Right now mine is just the basic bolt on parts but plan on doing H,C,I soon.
 
MAF interchange for 93 and earlier Mustang.

Swapping the MAF sensors between different MAFs is a big no no. The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

The exception to the above statements is if you have an aftermarket tuner system such as Moates Quarterhorse, Tweecer, or similar device. Then you can alter the computer's MAF transfer function table to match whatever MAF housing and sensor you have. The tuner device works in conjunction with a high quality Air/Fuel ratio meter so that you can tell what sort of air/fuel mixture you have a any given time.

The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

*1.) Metal flange adapter http://www.kustomz.com/components.html Buy the TR70 for $39.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
 
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MAF interchange for 93 and earlier Mustang.

Swapping the MAF sensors between different MAFs is a big no no. The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

The exception to the above statements is if you have an aftermarket tuner system such as Moates Quarterhorse, Tweecer, or similar device. Then you can alter the computer's MAF transfer function table to match whatever MAF housing and sensor you have. The tuner device works in conjunction with a high quality Air/Fuel ratio meter so that you can tell what sort of air/fuel mixture you have a any given time.

The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

*1.) Metal flange adapter http://www.kustomz.com/components.html Buy the TR70 for $39.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
 
Thanks for sharing your experiences with both C&L and pro m meters, if you don't mind me asking what kind of setup are you running, do you have H,C,I. Right now mine is just the basic bolt on parts but plan on doing H,C,I soon.

My car is an 89 gt with stock bottom end, 185000 miles. Everything was installed over 15 years ago. I realize its an old setup, but its been pretty solid so far.

Cobra intake
Edelbrock performer heads
F303 cam ( a little much for an auto but i like the upper range pull)
 
Ok, just an update, I got a mass air meter from a 94 mustang 70mm plugged right into my factory harness I already had an adapter.unhooked battery pulled my pro m 75mm meter off hooked the 94 meter up and car started right up idling went to about 1500 just like it used to slowly idled down to about 750 rpms took it for a test drive and no more hesitation, miss at low rpms car ran perfect.:):SN:
 
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Some things to check on the 75mm you just removed...
1. Was it dirty?
2. Was it the correct calibration for you ecu/injector setup?
3. Did you play with clocking it at all?

You found something that works, stick with it. But I always wonder about the 'why' does it work...
 
Some things to check on the 75mm you just removed...
1. Was it dirty?
2. Was it the correct calibration for you ecu/injector setup?
3. Did you play with clocking it at all?

You found something that works, stick with it. But I always wonder about the 'why' does it work...

The pro m was bought new about a month earlier cause my old sensor in my C& L went bad run like crap, bought new pro m and ran good except for hesitation at low rpms.i did try to clean it thinking maybe some oil from new filter got onto it.it is calibrated for 19 lb injectors. Tried clocking it but nothing seemed to fix low rpm hesitation.