I have the maf sensor from an 85 5.0 L TPI
Camaro and the computer/wiring harness from an 89 5.7 L TPI Trans Am. Will they be compatible? Somebody else said they wouldn't.
Thanks.

 

I'll answer you again, but in a different way... call your local parts store and ask them for a MAF part number from an '85, '86 and '89. You will note that the '85 is a different part number. The '86 and '89 have the same part number. If you really want to triple check, you could call GM also and do the same. IIRC the '85 is a digital MAF and the '86-'89 is an analog MAF.

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"Perfection is a trifle dull. It is not the least of life’s ironies that this, which we all aim at, is better not quite achieved."

-W. Somerset Maugham

 

But then why does TPIS sell replacement MAF sensors that they say will fit all 85-89 MAF TPI systems? Thanks.

 

Couldn't tell you why, however, you could always call and ask, or drop them an e-mail @ hpfarm@aol.com or hpfarm@tpis.com.

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"Only in Britain could it be thought a defect to be “too clever by half.” The probability is that too many people are too stupid by three-quarters."

John Major

 

They are all the same. Except the difference from the v6 to the v8 (Delco vs. Bosche) on 3rd gens.




[This message has been edited by JoelOl75 (edited February 19, 2001).]

 

Allright, here we go with the bogus info again. Here is the final post of a lengthy post on MAF operations that we had last March/April:


So there you go. On this board, I would say there are a half dozen of us that are pretty familiar with the MAF and it's operation, Vader is comfortably on the top of that list.

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"Only in Britain could it be thought a defect to be “too clever by half.” The probability is that too many people are too stupid by three-quarters."

John Major

[This message has been edited by Red Devil (edited February 19, 2001).]

 

I have an 85 MAF in my car with an 87 ECM setup, just so you know that in at least some cases they ARE compatible. You can see the info on my webpage below:

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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

 

Red Devil, your quote from Vader is WRONG. Vader corrected himself in a later post. All '85-'89 V-8 TPI MAFs had an analog output (not FM). They are all compatible. The only difference is their manufacturer (Bosch vs. Delco). BTW, the burn-off module is external to the MAF and irrelevant to this discussion. Check any '85 to '89 ECM wiring diagram or manual.

 

Yep! Thats completly incorrect! My '88 uses an analog signal that puts out on the green wire .5v to 5v

The only frequency generating MAFs used on 3rd gens were the delco (Not Bosche) used on the early 2.8L cars. They didn't have a platinum wire instead they used a mica film. I know this sh?t because I have a maf 2.8 and a maf 5.7 so much for being mis-informed. Yes the 4th gens use a frequency maf. You got that much right.

 

So, contrary to what some may say, the MAF sensor from my 85 IROC 5.0 will work with an 89 GTA 5.7 harness/ecm?? Thanks.

 

Are you guys sure? I called two parts places today and both have different part numbers for each. I tried GM but the lackey at the parts dept. couldn't even find me one number. I will look into this further now!!

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"Only in Britain could it be thought a defect to be “too clever by half.” The probability is that too many people are too stupid by three-quarters."

John Major

 

Greg,

Yes, I corrected myself later. I had transposed the information for the Delco FM and Bosch analog MAFs. I had first incorrectly stated that the Bosch MAFs were digital and the Delco MAFs were analog output. I had that information backward.

That doesn't change the fact that they were different. The early 1985 TPI engines had a Delco FM MAF, 8-bit processor in the ECM, 160 baud serial link, limited I/O, and non-emissions compatible programming (with a completely different ECM part number - 1226870) and a MAF module piggybacked to the outside of the ECM. The very few late 1985 TPI engines produced came with the 1986-type 16-bit, 8192 baud ECM (P/N 1227165) and Bosch MAF, no piggyback module, and had an entirely different electrical connector on the MAF out of necessity to prvent mixing the two. This is the reason everyone has two different part numbers for the MAF sensors. The GM V-6 engines continued to use the FM MAF, and GM returned to the FM control scheme when the MAF returned to V-8 engines in 1992 Corvette LT1s. Incidentally, the Delco FM MAF also supplied the IAT sensor reading to the ECM in early 1985 and later V-6 cars, so there is another difference worth noting. Still think they're the same?

If you can figure out how to plug in an early 1985 Delco MAF to the later analog harness, go ahead. I'll tell you where to find all the repair parts when you post back here wondering what the hell happened. For anyone that is wondering ahead of time, the ECMs are listed above. The later ('85½-'89) analog MAF is P/N 14094712, the 1985 MAF is P/N 14081243. The V-6 uses the same sensing element and electronics package in a smaller diameter housing, updated GM P/N 25007557.

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Later,
Vader
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"No matter how hard you try you can't stop us now..."
Adobe Acrobat Reader 4.0

 

If you can plug the MAF in it will work. GM thinks we are all idiots so they designed the plugs different. If the MAF has 3 wires its a FM (mica) sensor if it has 5 then its an analog output (platinum wire). I personally never saw (nor heard of {not saying they don't exist}) a 3rd gen v8 with a fm sensor.


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'88 Camaro RS 2.8L
'88 Formula 350 (Too many mods to list...)

 

While I could not get an answer from GM I have spoken with an engineer at Wells,according to their info there were TWO different MAFS produced for the '85 year. He was a tad busy, so I'll call again sometime next week to inquire further, if anyone really cares at this point.

 

Just look at the plug on it.... That will easily and quickly resolve the prob IMO.

 

Sorry Vader, you're close but still wrong -

My '85 has an 1226870 ECM with a BOSCH, 0-5 Volt out MAF. Swear to God.

Anyone interested in the truth, check this out:

http://www.ece.udel.edu/~davis/z28/ecm_swap/



[This message has been edited by Greg '85 T/A (edited February 26, 2001).]

 

Same here, up until last July when the above mentioned Mike Davis switched out my old 870 ECM for the 165. Still using the same old Bosch MAF sensor that had been in there forever.

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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/