more help please... where can i find my ecm part #?? and whats that little box on top of it???? thanks for any help....:hail: :hail: :hail:

 

That was GM's early attempt at the MAF Burn-off relay on their cars with the MAF sensor. The part number for your ECM should be on a label on the ECM.

 

MAF burnoff/power relay??? cause i cannot find it under the hood...

 

Uh Huh, I will post the schematic on it later.

 

the dude i bought the car off a few months says he put an 88' 5.7 tpi in the car (he scrapped the original 305 that came with the 85') but the ECM looks like its the same one that came with the car... is it possible for 85 ECM to work with the 88' 350??? and he also cut the a.c and did some other stuff. any idea why? or any info would help me... car stil runs strong though.... thanks y'all :lala:

 

HEY TRICKSTER JUST WONDERING IF YOU POSTED THE SHEMATIC OR WHERE? I THINK THIS COULD BE HELPFUL TO ME ALSO. THANKS

 

No, I hadn't posted it yet as things have been a little hectic the last few days. I will post it now.

P.S. JohnC005, If you would, please leave the "CAP" key in the "OFF" position when you post. It would be most appreciated.

 

What you have there is a 1985 870 ECM and MAS module. The MAS module performed the MAF burn off and power functions, therefor there are no MAF power or burn off relays in that system

And BTW, that ECM is NOT the one that came from the factory..it is painted black, GM didn't do that.

 

Maybe my eyes are going bad or I am just blind and can't see straight. But I could swear that item in the above picture that is between the fuses and MAF sensor says "BURN-OFF RELAY" at the right hand edge. But if what Morley says is true, that must be a figment of my active imagination.

 

Trust me, that "little" silver box is not a "relay", it is the MAS module. If it were just a "relay" GM wouldn't be charging $700+ for it. The module contains a printed circuit board with a small relay mounted on it (presumeably for burn off) 2 IC chips, a myriad of resistors, diodes etc and a 5V power regulator which I would assume to be for MAF power.
Is the schematic you have there for an 85? All the schematics I have (from GM and other sources) just show the MAS module, no internal components for it since GM bought them from Bosch.

 

$700.00 Wow and I have a perfectly good one sitting in a chair beside me for sale, Wonder how much I can get out of it.

 

Yes that schematic is from the 1985 GM service manual for the Camaros. And yes I agree it is rather high to have a new one from GM. Here is a picture of it from the 1985 GM Camaro service manual showing it and the ECM. It is referred to in the manual as a "Burn-off Module". BTW, in the trouble code section for the 5.0 TPI there is only a code 33 & code 34 listed. I can post those as well.

 

Yes, they call it a burn off module, but it is also MAF power. When you do the 165 conversion you tap into the MAS module harness for the power (the switched ground to allow the 5V) and burnoff relays. And yes, the 85 only lists codes 33 & 34...this means ...what? They had no codes for a failed MAS module.

 

In several of your posts morley, you have referred to a MAS module. Exactly what is the MAS module, I'm unable to find a reference to that in the service manual. Also in another of your posts you mentioned that the ECM was not the one that came from the factory because GM didn't paint the ECM's black. That's interesting because the 85 Z28 that I bought off the showroom floor in 1985 had a black ECM in it.

 

I have a 1985 TPI and it came with a 1226870ECM With a piggybacked BOSCH MAS module #14080620 and the ECM wasn't painted. But Maybe I will Paint My 122730 that is going in Black, I kinda like it.

 

P.S. JohnC005, If you would, please leave the "CAP" key in the "OFF" position when you post. It would be most appreciated. [/B][/QUOTE]

TRICKSTER, I DON'T UNDERSTAND WHY YOU DON' LIKE ALL CAPS, IT WAS YOUR PICTURE THAT WAS TOO WIDE FOR THE PAGE NOT MY CAPS LOCK! OR DOES IT BOTHER YOU TO READ THIS WAY?

 

TRICKSTER, I DON'T UNDERSTAND WHY YOU DON' LIKE ALL CAPS, IT WAS YOUR PICTURE THAT WAS TOO WIDE FOR THE PAGE NOT MY CAPS LOCK! OR DOES IT BOTHER YOU TO READ THIS WAY? [/B][/QUOTE]

No, it doesn't bother me to read it this way and it is not a case of me not liking all caps. It is just considered to be impolite to use all caps when posting on the internet. Sort of like someone yelling at the top of their lungs during a normal conversation like the other individual has a hearing problem or something to that effect.

 

It is just considered to be impolite to use all caps when posting on the internet. Sort of like someone yelling at the top of their lungs during a normal conversation like the other individual has a hearing problem or something to that effect. [/B][/QUOTE]

I appologize for the poor posting ediquet or what ever its called. I did not mean to yell at you like you are hard of hearing, I am just a little rusty on my typing skills and it is easier that way.
By the way, thanks for posting the scematics, helped alot.

Doug

 

Doug,

Glad the schematics were of some help to you. If you need any others let me know.

 

Straight from GM service center: "Some remanufacturers even paint their ECM's, GM never paints their remanufactured ECM's" The only painted ECM's I have ever seen had a tag from a third party stuck on them.

Every schematic I have on the 85 TPI (I have several) calls it a MAS module as does the GM parts catalog...like Rock Auto's listing

ACDELCO part# 21652
Module, Mass Airflow Sen (#14080620)
**None stock item, shipping delayed up to 3 business days**
Price $783.99

From AC Delco
P/N: 216-52 MODULE,MASS AIRFLOW SEN

OK? MAS Module

 

In other words they made one word of air flow so that instead of calling it a Mass Air Flow (MAF) sensor module they now call it a MAS module. OK!!!!!!!

 

Yes, thats why it is all caps, its an acronym.

 

I'm sitting on 3 of them myself, along with an 85 and 88 harness

 

so to sum this all up, basically the guy who put the 88' tpi in my 85 irco kept the same ECM and original MAF (located on top of the ECM) ???? and does that explain why i donot have a relay under my hood on the driver side???? (i only see two..) on more thing, i assume i have MAF because my air filters split like a letter 'Y' ??? thanks guys........

 

Yes that would be correct, the 85 TPI cars did not have the MAF power or burn-off relays under the hood. This was the first year that GM had used a TPI engine in the car and were still in the learning stages. The module that you have was their attempt at a control module for it. In 1986 they incorporated it into a better designed ECM and did away with that module by using relays in the engine bay.

 

thanks trick!!!!!!! so it is poss for an 88 engine to use an 85 ECM???? and all other stock components??
:hail: :hail:

 

Sure its possible, the sensors and such are all the same except for the MAF itself. For an 85 MAF ECM you need to use an 85 MAF sensor BUT, you can use the 85 MAF sensor on 85-89 MAF systems. The 85 MAF uses a pulsating signal, the others did not but they can use a pulsating sensor (85).

 

thanks alot morley and trick!!!!!:lala:

 

If its not a problem I just wanted to ask real quick, how much is different about the 85 to the 86? I have an 86 and u said something about relays under the hood, so should my 86 MAF have that MAS module?


And is there somewhere to find all of those diagrams that you post Trickster? or is that from a book

thanks

 

1985 is the only one with a MAS module the 86 has the relays next to the brake booster on the drivers side fire wall

 

i think i got it fixed guys! i took of the peice of crap privacy protection and it seems to be working fine now... it was messing up my sites!!!! thanks...

 

oops! wrong thread....

 

Just as stated here. No MAS module on an 86+ TPI, but that's only the beginning of the differences between 85's and 86+. The ECM, PROM, harness, MAF sensor....big changes from just 1 year.

 

it's possibly for them to change the 305 to a 350 but without modding the computer the car will run terrible. i swapped my 305 to 350 and the thing ran like it was a 2.8 running on 4 cylinders. had a check engine light. i installed a chip and that problem was solved, so unless there is a chip in the ecm or a different ecm i would doubt he put a 350 in it unless the car runs like a yugo. even the injectors, if they put the 350 in and still had the 305 injectors that will cause i big problem too. i ran 305 injectors in my 350 because i thought there was something wrong with my 350 injectors and you can forget about it. the car wouldn't idle, i had to throw it in neutral and keep it revved in order for it to stay running and putting it from reverse to drive now that was terrible. i had to neutral drop it in order for my to get it in drive cause as soon as i took my foot off the gas it would stall. now my car isn't tpi but i'm sure you have to do the same stuff with the tpi that you would have to do with the throttle body. so maybe if you get the service number on the ecm and see what application it's for, or open it up and see if there is a chip.. and if everything is coming back to being for the 305 i wouldn't count on it being a 350.

 

its definitly a 350 with the factory ECM and its fast as hell! dont know or what he did but it runs fine... its a complete engine, tpi and rails, etc....

 

Out of three Camaros with an 870 ECM that I have parted out, two were painted black. I can't say for sure that they looked original and not remanufactured, because I didn't pay attention to that at the time. Just thought I'd throw that in here.