Cobra MAF?

88LX5.Oh

15 Year Member
Dec 30, 2011
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Arkansas
Can I use a Cobra MAF? On latemodelresto, they have a "Cobra" MAF sensor made by Pro-M and was wondering if I could use it on my 88 LX. It has the connector style I need and it's calibrated for my injector size and it's 75 MM (I have a 70 MM TB)
So is there anything that would make me not be able to use the "Cobra" MAF sensor?

Here's exactly what I'm talking about
http://www.latemodelrestoration.com...bra-50L-75Mm-Black-Pro-M-Mass-Air-Meter-For-2
 
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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 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 the stock A9L,. A9P or A9S computers which are setup to use 19 lb injectors.
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/cat3.html Buy the TR70 for $44.95. 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.
 
The only reason I was looking at this Cobra MAF was because it had the proper connector on it. When I went to mass air, I had a random ford MAF sensor and housing laying around (circular style connector on MAF sensor) and a huge 80 MM Granatelli housing. Car ran like crap. My father then took it upon himself to cut the connector and wire in the Granatelli sensor (had a rectangular connector) and the car ran good for a very short time then started having really bad idle surges from about 800-1200 RPM. What I'm wanting to do is get a smaller housing along with the correctly calibrated sensor because I don't feel the need to have a humongous 80 MM housing and a sensor that is calibrated for only God knows what kind of injector. Well supposedly the MAF (and housing) came off a '97 F150 with a supercharger and 42 lb injectors (I actually have said injectors and supercharger). So, if the MAF is calibrated for 42's, would this cause the engine to run lean, and then compensate and go too rich, then back to lean, causing it to idle surge? And should I just swap back to the circular style MAF connector and then buy a MAF for 24's?

I'm getting so close with my car, so that's why I'm asking so much lol. Any help is much appreciated.

EDIT: I'm reading your Surging Idle Checklist right now to see if I can find anything about my idle there
 
really ? I'm pretty sure that u need to calibrate mass air meters for the injector your using seeing as I have a pro-m 75 calibrated for my 19s and helped a friend build a turbo car with a Maf calibrated for 60s .... the eec is not where the difference is its the maf sensor and it's calibration ....
 
really ? I'm pretty sure that u need to calibrate mass air meters for the injector your using seeing as I have a pro-m 75 calibrated for my 19s and helped a friend build a turbo car with a Maf calibrated for 60s .... the eec is not where the difference is its the maf sensor and it's calibration ....

The MAF is just an analog device to measure airflow: it knows nothing about injector size. Aftermarket "calibrated to injector size" MAFs just bend the transfer curve function to lie to the computer about how much air is flowing through the MAF. The MAF output is in the 0 to 5 range: more voltage means more airflow. If there is 0 volts or 5 volts coming from the MAF with the engine running, the computer sets an error code. Five volts means the sensor has maxed out or has an internal failure, zero volts means the sensor has failed or there is an open circuit in the sensor wiring path.

The computer is where the smarts are to set the injector pulse width, which is what determines the fuel delivery. The computer takes input from the MAF, MAP, ECT, ACT, TPS, O2 sensors and RPM and uses the data to calculate the injector pulse width. By lengthening or shortening the injector pulse width, the computer controls the air/fuel ratio. The computer's internal program has lookup table locations that uses the data present to represent the injector size and flow rating and the MAF transfer data . Modify those locations with a Moates, Tweecer or other tuner and then you you can use almost any MAF that is Ford EFI compatible. That's the same thing that a custom dyno tune chip does for you.

See the following for more help:

http://www.allfordmustangs.com/Detailed/583.shtml

http://www.veryuseful.com/mustang/tech/engine/#EEC
 
Fixed the hanging idle issue, thanks to your checklist Jrichker! Your advice is always wonderful. I still have a slight issue though, that I feel you could help me with. (this has happened multiple times) If the car sits for a while, I can start it up with no issue at all and it'll idle at about 900 RPM perfectly. I then try to move it outside of the shop because I don't want to inhale too much exhaust fumes. If I don't keep the RPM's super high backing out, it'll die. I then try to start it and it won't unless I give it almost full throttle. When it starts back up, I have to rev it up a few times to "clear it out" and I can look back and see smoke (unburnt fuel I'm assuming). After I clear it out and let it sit, it'll idle fine, then if I rev it, it'll rev down to about 1000 RPM, kick up to maybe 1200 or 1300, then it'll surge from 900 to around 1300.

What could be causing it to run good one minute and then surge the next?

Also one more thing, I have turn downs and you can see on the ground where there's black residue coming outta the exhaust. I'm assuming it's unburnt fuel. A calibrated MAF will fix this issue or at least make it better, correct?
After I get it running okay I'm gonna get it dyno tuned because I know the calibrated MAF's aren't perfect. I just want it running as best as possible before I trailer it 2 hours away and spend over $600 getting it tuned.