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Hello All,
I am new so if this has been coverd, just send me in the right direction.
I bought a 87 GTA LB9 M39 and love it. I'm coming from a gen2 W72 T/A so this computer stuff has me ready to take a long walk/short pier. I've been fighting the succubus of all codes .....33 and 36. I had bought the Duralst DL-6014 MAF from autozone because it was mentioned on here to be a copy of a Wells unit. No matter what I did, what relay I replaced or switch, or sensor....itd run great for a short period, then like junk..I'd fix again, clear codes, good for short, then crap. So after flowchart, I began looking for another MAF. I happened to notice on Rock Auto, for the selections, there was a Walker manufacturer that ( in tiny tiny parenthesis) it stated "unit does not have maf burn off circuit"
I thought....thats curious....what is the computer going to do? How is it going to try and react?? So on a hunch I called autozone and asked if DL-6014 did infact have the b/o circuit and low and behold...
NO BURN-OFF CIRCUIT !!!
The info I had showed that it was a match for the deloco part#. Not equil to or similar as....
I called another manufacturer that I had ordered 1 other from and just thought dead on arrival...same.. I read where 1 guy boutght 7 different mafs before he ¹ "found one that worked".. .
so I'm on #5 my self. And I bet your left pinky toe, that when I get all the emails back....none of these have the burn off circuit. That's why they didn't work I bet. Not that they were d.o.a.
So does anyone know if there is a surefire way to tell if it has the burn off circuit by looks? The number of elements in housing or something???
I will absolutely call tech dept of every one I bought. I have about 14 hrs of wasted time looking for a short in a wire, in the factory harness, that never was.
so I guess the moral of the story, be sure you know what you are buying. And remember
just because they say it "fits you car" that doesn't mean that it'll WORK on your car, they just assure fitment. Not work-mient..
so my wait for freedom begins again. Please fed-ex don't let me down.
All in all, it's been great learning new things though. Reading all the blogs and seeiing the many differnt sides and opinions people have about our birds. Very interesting and exciting. My grandpa said all the time... if you don't learn something new every day, it wasn't worth getting out of bed.
Take care! Ill update asap.
but if anyone knows for sure of a brand that has maf b/o circuit, lmk. I'm Aggie by blood and wouldn't mind having a backup haha.
thanks!
jh
....
These cars are picky about which MAF is being used, I prefer used Bosch but they are getting harder to find and run the gamble of a 30 year old used electrical part. As long as your wiring/grounds are good and no vacuum leaks, which it sounds like you looked for, it may just be sensors not calibrated correctly for your car.
That being said have you looked at any of the reman Bosch units? BSE 27854 looks like the original Bosch with the hot wire for burn off and so does Cardone 744712 and a few others on Rockauto.
I am no expert but typically if you compare the different MAFs you notice the reman Bosch have the wires in the middle of the sensor while the others have what looks like a chip in its place. Also the reman Bosch has all the Bosch markings that the factory unit had.
This is the Bosch style that you want.
This sounds like what the ones you purchased look like?
The duralast sensor you mentioned is the older design of the MAF pictured above, your code 36 is likely related to no burn off in those style sensors and the code 33 for high airflow could be a result as well of poorly calibrated part. There was a report a year or so ago of a member who found the Delphi MAF giving high readings, was a bad calibration tjst Delphi was going to correct…
As a matter of fact, the one I have on my car now is the BSE 27854. I just received it yesterday. I am replacing my negative battery wire at the moment. I have taken the neg wire off so many times in the past few weeks, the head stripped and rounded. Needless to say, i was a little peaved a few times and put the kung fu deathgrip to it with a pair af vice grips... oops...About done and was goigoing to cross my fingers and try it . I bought it off Amazon, said it was Borg Warner. I thought it a little odd because I thought those guys were more transmission/gears/driveline sorta thing. I opened it up and there was the Bosch plate staring at me. I sent a message to the seller asking about the hot wire and got a reply basically saying idk....lol.
How do you go about calibrating one? I had read where the "clocking" was important. Most of the ones I have bought (1) look just like those in the pics you sent, but had 1 or 2 notches. I would use the one that was closest to being perpendicular with the little elbow housing coming out of the air filter housing. One or maybe 2 mafs I bought didn't have a/any notches, so I researched it and about the only thing I could find was here (gave up looking anywhere else on the innerweb shortly after) saying the elements needed to be as close to perpendicular as to not cause turbulence. But that maf didn't work, obviously, so back to feeling like i was trying to put square peg/ round hole. But I believe that I have found the solution with what I discovered this evening. Or at least I hope.
but if you could enlighten me on the calibrating part, I'm all ears. I'm out in the armpits of West Texas, oilfield capital, Midland/Odessa. Oilfield and related jobs are very odd hrs, so just anytime.
it's funny that you commented, and I am very grateful byw, because here's a pic of t
he ornament on my rear view....
As a matter of fact, the one I have on my car now is the BSE 27854. I just received it yesterday. I am replacing my negative battery wire at the moment. I have taken the neg wire off so many times in the past few weeks, the head stripped and rounded. Needless to say, i was a little peaved a few times and put the kung fu deathgrip to it with a pair af vice grips... oops...About done and was goigoing to cross my fingers and try it . I bought it off Amazon, said it was Borg Warner. I thought it a little odd because I thought those guys were more transmission/gears/driveline sorta thing. I opened it up and there was the Bosch plate staring at me. I sent a message to the seller asking about the hot wire and got a reply basically saying idk....lol.
How do you go about calibrating one? I had read where the "clocking" was important. Most of the ones I have bought (1) look just like those in the pics you sent, but had 1 or 2 notches. I would use the one that was closest to being perpendicular with the little elbow housing coming out of the air filter housing. One or maybe 2 mafs I bought didn't have a/any notches, so I researched it and about the only thing I could find was here (gave up looking anywhere else on the innerweb shortly after) saying the elements needed to be as close to perpendicular as to not cause turbulence. But that maf didn't work, obviously, so back to feeling like i was trying to put square peg/ round hole. But I believe that I have found the solution with what I discovered this evening. Or at least I hope.
but if you could enlighten me on the calibrating part, I'm all ears. I'm out in the armpits of West Texas, oilfield capital, Midland/Odessa. Oilfield and related jobs are very odd hrs, so just anytime.
it's funny that you commented, and I am very grateful byw, because here's a pic of t
he ornament on my rear view....
I should have clarified, when I say calibrated I meant the electronics in the sensor that the manufacturer has set. The non Bosch style ones seem to record more airflow IIRC than the Bosch that can cause the computer to make changes resulting in poor running. I think I saw an old MAF on eBay once that was made by BWD, I don’t know much about them though.
Keep us posted if that BSE MAF works out when you get your terminal switched out, those side posts can be fun right.
That's a big 10-4, absolutely will.
Yes, the side posts are all types of not fun. I still blame DeLorean and his dang ol cocaine cowboys for that casserole of nonsense.....
Hey reddragon,
so as it turns out, most of the maf sensors I have do actually have the burn off circuit. The Specter does, the re-man bosch of course, and the 2 off of Amazon. or about 85% sure the Amazon one's do. They are the same weight, as the o es with. The Autozone Duralast doesn't, and it was much lighter. Pretty sketchy way to determine that they do, I guess, but they all run about the same in my car. The throttle response was better than the previous one when I was swapping them in and out yesterday. Unfortunately the Bosch re-man wouldn't let my car even idle. It would turn over, but wouldn't stay running for even 2 seconds. But it was shipped poorly, no kind of packing material at all. Not even sealed up in a bag, like every other 1 bought. I'm sure it took a beating like every other package that comes out this way. Biggest pain of it all though, even though the 3 left run well in my car, code 34 is still triggered. But the 33 and 36 codes are history. So 2 steps forward and 1 back is still progress I guess. About to flow chart it. Let ya know
MAFs should be stored/shipped securely as if they get smacked around that can damage them pretty easily…that being said you have tried many and still not much change. Have you replaced the MAF power and burn off relays? I forgot to mention those earlier, they are cheap and easy to replace.
If that doesn’t help, what RPM does the engine idle at warm? How does the car run without a MAF plugged in? Have you verified with a multimeter or scan tool that your throttle position sensor is set at .54? A guy named Jrobling has a good video on YT checking/adjusting TPS voltage.
Has the throttle body ever been deep cleaned? I mean pull it off the plenum and really go to town with throttle body cleaner and a tooth brush, really cleaning up the throttle plates, bores and passages, IAC etc. That can cause problems as well
Have you tried to smoke test the intake? Maybe check your rubber MAF ducting for holes? I’m wondering if you are having unmetered air enter through a vacuum leak. Easy way to test that is a $5 harbor freight fluid exchanger on the vacuum port on the passenger side of the plenum and a cheap cigar, there is a good YouTube video on it and the smoke test is the best way to check for vac leaks IMO.
If all else fails I would either purchase or find a local shop that has the capability to get live data on this OBD1 set up (not a ton of shops do anymore but you might get lucky) to see exactly what’s going on, without live data it’s like poking around in the dark and you don’t want to fire up the parts cannon and just waste more $ and not even fix it.
A snap on MT2500 is a solid scan tool that can still be found used but you want to be sure it has the right cartridges for your car or ask a prospective shop if they have one and still work on obd1.
Last edited by Reddragon88gta; 02-08-2024 at 03:05 PM.
One thing I forgot to add if you do the smoke test is cover the front of the throttle body with a latex glove to keep it sealed tighter for easier detection of a leak.
Hey man,
sorry for the delay in updating. Its been a wild ride. I bounced back and forth with 34 code, then 36 and 33. A Delphi Maf sensor I bought would not through any codes, but it would not run. I couldn't get the car to get above 2800 rpm. It would eventually run so rich, your eyes would burn. I'd put in a Bosch reman and the car would run fine for a bit, but 33 and 36 codes were thrown instantly almost. Re placed all pig tails, went round and round with relays, and was about to sell the car. I had a Maf sensor bought off Amazon that I couldn't return and thought was bad or no burnoff circuit. Couldn't get and answer from manufacturer if it had the circuit. I put it on the shelf and saved it for target practice. After tracing through enough wire to get to China, and for sh+$ and giggles, I decided to just try it again after all the fixes and repairs. We'll SHAZAM. NO MORE CODES!!!
It was from a company A Premium?
So hopefully this is a done deal!
02-03-2024, 10:40 PM
