i know that with my car after a certain period it goes through a burnoff process where the MAF gets 12 volts and it burns off any crap thats on it.

i know that in order for this to happen, the computer GROUNDS the wire on the burnoff relay to complete the circuit and supply the 12 volts

my question is, WHEN exactly does this happen? right after the car is turned off after being in closed loop?? is it every time the car is turned off??

i have a code 36 and i connected a test light to the ground and to a 12 volt source. it is connected to the ground right out of the computer that leads to the burnoff relay, when i run the car, the light never turns on, and it doesnt turn on when i turn off the car.

does this mean that the comptuer is simply broken and never grounding that wire and that is why i'm getting the code???

sorry this is long but this has been killing me

 

thats a sticky situation i had the same prob as u except mine was throwing code 34 i think but coulda been 36....the code was defined as maf burnoff.

the maf burns off its contaminents everytime the ignition switch is turned on then off, every time and easy way to tell if the MAF is the cuprit is to diconnect your air intake ducting exposing the maf simply start the motor and let it run for a min then have someone turn the engine off, with u looking at the maf the wires should turn to a bright red glow, if this happens then your maf is working correctly and so is your relay system and ur computer is just freakin out lol. if it doesn not glow then ur comp/MAF/or maf relay is bad. the maf relay is located on the driver side firewall there are 3 identical relays for the fuel pump, maf, and then the maf power relay, i got lucky and my maf relay burnoff was printed on the top of the relay, simply disconnect the burnoff relay and and replace with the fuel pump relay and try again except dont turn the engine on, just turn the key to the run position and hear is the relay clicks and ur pump turns on, if it does then ur relay is fine, if it doesnt its bad and needs to be replaced. simply switch back the relays and start the engine again, to tell if the MAF is bad while the engine is running nock on the top of the maf and if idle of the engine changes then ur maf is bad, if not ur in the clear so far. if u have a replacement maf like i had from a 86-88 TPI 305 or 350 simply just replace and see if the code still happens. if its not ur MAF or relay then its ur ECM.

i did all this and found that i would only throw a code certain times, i did everything and it all seemed fine i even tapped on the MAF with the motor running and nothing happened, but i changed out the MAF and the code went away so my MAF relay system in the MAF musta been bad. havent thrown that code since. good luck, sorry this is so long too

 

first dont apologize about it being long, i appreciate every word.

i've tried all the things you've said already, the only thing i havent done is looked PHYSICALLY inside the MAF to see if the wire is turning red, but i have reason to believe that it can't be, because i connected a test light to see if my comptuer is EVER grounding that wire that needs to be grounded in order for the circuit to be complete. i took it for a ride just now, waited for it to go into closed loop, and then turned off the key while staring at the light and it NEVER turned on, which means that wire is NEVER being grounded. this is what i'm talking about:



so basically i think i've come to the conclusion that my comptuer is bad, so i'm reseting it and i'm going to see if that light ever turns on while i drive it for the next few days

 

man i like that drawing lol that looks like a hanyes manual...haha jk

oh ok i understand, so u checked everything and its fine... u cant get ahole of the maf from a friends TPI just to check it? i had sorta the same probs that u had and my car ran fine but i would throw the code randomly. just to be safe i would replace the maf just to test it, ususally part stores allow u to return products if u dont use them, just plug it in and see. as far as fixing it...ur in a delema, the MAF and ECM are the most expensive parts of the system, a stock maf i believe is over 150, high flows around 300. ECMs are gona cost u a pretty penny too tho, i would find a way to make sure its ur ECM, i think that ur test light is a good idea and if u feel comfortable in believing that for sure its ur ECM, then i would just replace it and hope it works, good luck

 

I'd check the MAF relay and the fuel pump relay before worrying about the ECM or the MAF itself.

 

I had a burnoff code in my '89 IROC, and I replaced every single relay and sensor in that circuit. Burnoff relay, oil pressure, MAF, etc. I thought it just couldn't be that ECM. Guess what? It was. You know what really sucks? The core charge for that ECM is more expensive than a new one when I got it at Autozone!!!

 

yeah i know, thanks a lot by the way to everyone for your help.

the only thing i have to say is, this will be my THIRD time buying a new ECM...... i've already replaced it twice, and both times it has fixed my check engine light problems....... i just dont konw WHY i keep killing ECM's over the past 3 years i've gone through 3 of them???

the only thing i think is the reason why i would keep killing them is maybe because the voltage is not correct on my car, and maybe its messing them up b/c they have insufficient voltage?

i've replaced the battery and the alternator twice. the only thing i think might fix the voltage problem is changing the harness connected to the positive terminal on the battery, i know that the screw is stripped and doesnt make a great connection there... just dont know how to fix it.

my voltage stays at 12, but when i use the rear defroster or any other accesorry like the window motors, it goes down to like 9, and stays there until i let go of the switch......

any sense of that??? sorry this is so long again

 

I'd start looking for a bad ground connection or maybe a wire in that circuit is shorting out somewhere?

 

yea a bad connection at the batt will kill an ECM, just buy a new batt cable with new screw or replace the screw like i have, u can get the lead ones from Kmart lol for like 6$. i would def do that, as far as blowing them it could be the grounds, there are soo many with TPI cars a bad ground would do it too. yea dont worry the rear defroster does the same thing with all our cars, they eat up alot of juice. i just roll down the windows lol i dont care bout the weather.

 

haha alright well i officially checked the MAF and its fine, i physically grounded the wire right out of the ECM, looked inside the MAF only to see a BRIGHT red wire glowing back at me, so i know that the actual maf is just fine. i'm leading towards the ECM more and more.

i drove the car today 20 miles and never saw the light that i put in turn on, so the ecm is offically NEVER grounding that wire, at any time.

knowing that, and that the MAF is fine, and that the RELAY is fine, it has to be the ECM.... so before i change the ECM i'm going to try to figure out why i keep blowing them. i'll try everying you guys have said, hopefully this will be the last time i blow an ECM.

also one thing i forgot to leave out was i DID blow a heater core last year way after i put in the last new ECM. so some coolant MIGHT have gotten on the ECM and killed it, but i think that its unlikely.

thanks again everyone, ill keep you all posted

 

u can rule the heater core explosion out of the ECM killer...ive replaced these and they are basically shrouded completly and the ECM isnt really that close to the heater core, i could have happend but very very unlikely, when u tear it out i would look for coolant oxidation or dry coolant marks. yea just check all the grounds especially inthe engine compartment.

 

yeah i figured it was unlikely but regardless yeah, i'll get on top of the power and ground connections... hopefully i can solve the problem this summer when i get some time on my hands

 

hey custom, how do i put the screw in though? i dont know how to put it into the harness if i buy a new one