This is the list of known MAFs that will work properly with the stock A9L computer. Notice that the 93 Cobra MAF is not listed.

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,

 

I believe you can add the 91-93 Thunderchicken 5.0 to that list. Someone with an interchange manual posted on another site that one shows being interchangeable too.

I think the 93 Cobra had a 70mm maf, and supposedly the Thunderchicken Super Coupe(Charged) has a 70mm maf that is the same too.

 

The '89-'95 Taurus SHO uses the exact same 55mm MAF as the Fox 5.0's.

 

There are a few threads pertaining to this subject that should come up under a search. The problem within those threads is the confusion among participants as to who is talking about swapping the entire MAF, electronics and the aluminum housing OR who is talking about swapping the electronics off their functioning stock MAF and then installing that on a better flowing MAF housing such as the '93 Cobra/Thunderbird/Cougar 70mm unit, similar to what you have to do with the C&L units. All of this is assuming that the stock 19 lb/hr injectors are still being utilized.

In any case, good luck.

 

Never really got a conclusive answer on MAF electronics TESTING. Is there a way to test a used MAF short of installing it in a known running vehicle?

 

To test a sensor, you will need to check its output relative to its input...

To test an ECT/ACT sensor you need to subject the sensor to some TEMPERATURE....

Thus...
To test a MAF, you need to have airflow... and KNOW what that airflow is....


Sorry, but I don't see any way to reliably test a used MAF sensor.
However, they are fairly reliable...



jason

 

My guess is that for a small fee (small is subjective) the folks at PMAS would be happy to put one on their airflow/voltage machine and test it for you. But I'm not sure you won't find out what you need to know simply by trying it.

Also --- the list above of 'swappable' maf's --- I've not seen the actual transfer functions (mass of air vs voltage) on each unit, but I doubt if the transfer functions are all the same. My guess is that, over time, folks have figured out that you can swap this one in, and the car runs pretty well. Even the SN94/5 70mm meter swaps in and appears to work great -- but the ecu's adaptive strategies make up for the slight difference in transfer function between the two units.

So, my guess is that there is actually no other maf out there that has the exact same transfer function as the 89-93 HO unit. Just a bunch that appear 'workable'. Take care though -- this area is EXTREMELY misunderstood by most folks modding these cars. The 93 Cobra 70mm maf would see to be a swap candidate. At low airflows, the transfer function matches up pretty nicely with a stock 55mm HO unit. Problem is that as airflow (rpm) increases, the voltage signal becomes increasingly mismatched to what the ecu is expecting. Result? Up to 20% (more than the ecu can adapt to) lean at high rpm. It starts, idles and drives around town just like a stocker, but problems lurk at the top end. I wonder how many in the list above share the same trait? Unless you compare transfer functions side by side, you won't know....

Trey - the 93 Cobra is missing for good cause -- tell us what you know about the transfer functions of the rest of the list - have they been compared to the 55mm HO maf's curve?

 

Trey - the 93 Cobra is missing for good cause -- tell us what you know about the transfer functions of the rest of the list - have they been compared to the 55mm HO maf's curve?

Obviously, I'm not Trey...
But...


If you compare the Transfer of the MAF from the 94-95 Mustang (which is a 70mm housing/F2VF sensor) to a Fox Mustang Transfer (55mm/F1ZF), you will notice that they are nearly identical.

The list of MAF meters provided by Trey are all 70mm/F2VF units.
They will all directly swap...

In fact, you can walk through a j/y and probably find more applications that this meter (70mm/F2VF) was used on.

 

As said, you'd need a setup similar to PMAS to test a MAF. I think PMAS charges ~$100 to test a MAF and return a flow sheet.

The stock MAFs are accurate to ~+/-3%. So, if you look at a curve and you see max of a ~1-2% difference *at ALL points*, then the MAFs are effectively "the same". Ideally, it'd be nice if the MAFs were at least 0.1% accurate. That's the approx accuracy of the EEC's ADC (analog to digital converter - 10-bits). But, then the air flow input, and ?all? inputs get further scaled down to allow for faster calculations in the very slow "8051-like" 8-bit CPU.

You can *not* reliably swap electronics. Because of real-life mechanical and electrical tolerances, every sensor *must* be custom tuned to a specific MAF body.

But, the tolerances are "close" and the EEC can handle ~+/- 8%, and depending on if your MAF curve goes high/low and if the EEC was adding/subtracting, swapping electronics "may" work. Yea, risk f***king up your engine and drive-train because you were were too cheap to get a used MAF, or you followed some RICER advice, and swapped electronics - not smart at all!

There are a number of "techy" issues about accuracy and where it's important and the different effects each error source introduces. Basically, don't swap electronics, don't use a C&L, don't use a MAF with a different curve, don't modify the MAF in any way (bore it out, removes posts, etc), and the many (but not all) of the old Pro-M MAFs are junk unless you put the custom air flow into a chip. If you do any of the previous, then it may or may not work. As a famous quote goes:
"You've got to ask yourself one question: 'Do I feel lucky?' Well, do ya punk?"

_________
Joe
Electrical/Computer Consultant
AKA: A paid whore!

 

Okay, thanks to everyone for weighing in here, no way to test a used one short of sending it off.....not going to happen for a junkyard part.

Reading this post brings up another question I have. I keep seeing "don't use a C&L." Why is that? I recently grabbed a MAF from a 94 or 95 Mustang 5.0 at the junkyard. When I turned it over and looked, it's a C&L housing with Ford electronics meter(F2VF) on it. What is bad about C&L's? Is the problem with the alum. housing, or C&L's electronics...if they even make them.

I'm not sure what size the C&L housing is, where inside it do I measure to find out, inlet, outlet, middle?

I was happy to read that the F2VF meter would work with an A9* ECU as that is what I plan to use, A9P specifically. I'm thinking I need a larger(larger than stock HO 55mm) dia. MAF since I'm running a 351W Lightning engine.

I looked into the MAF conversion that FMS used to put out for the Gen 1 Lightnings. It came with an 80mm MAF, 30lb injectors, and obviously a new ECU.

My initial plan was to use a 93 Cobra X3Z ECU with 70mm MAF(from a SC 90's Thunderchicken, supposedly same as 93 Cobra), & 24lb injectors. However, I've read lots of disparaging things about the X3Z ECU. I already have the X3Z so I could still go that route.

So......to pull this all back to the original point........what MAF would you recommend using on a 351W with an A9P ECU? F2VF C&L housing MAF, stock 55mm 5.0HO MAF, 70mm Ford F1SF(if I remember correctly) MAF?

 

Also keep in mind that a lot of mafs from different ford vehicles are identical but ford installed them with different airboxes in different vehicles. This would cause ford to use a different transfer function in the ecm. This is also the reason they have the same part number but slightly different transfer functions.

 

Do you have an example of where Ford used the same Housing and Sensor, but a different MAF Transfer?

I would love to hear more...

jason

 

http://www.massairsystems.com/FLOW.htm
$35 to flow a meter, real good deal IMHO

I used a 93 Cobra meter on my 93 GT for years with ZERO issues and it worked better than both the OEM 55mm, C&L 76mm, and Pro M 75mm.