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a few weeks ago I had a code 34, but also found a massive vacuum leak on one of the intake runners so fixed that and car runs great. Then dealt with a code 42 and no spark advance...changed the icm and I have that fixed. Car was running great then dies, it fired a code 33 and wouldn't restart..unplugged the maf and it started up. I unplugged the batt to clear codes, restarted with maf plugged in and no code and it runs...check the scanner and gm/sec air at idle is 8, I rev up some and let it run and 5 min later the code comes back and it's barely running..gm/sec drops to 6, then 5 and it dies. I switched the maf before but figured the vac leak caused that code...I hate to go rebuy the maf again but I can't figure what else might cause this, it was running great and out of nowhere the code goes on and off with restarts.
Before I go buy this maf again I figured I'd ask for advice.
Thanks again,
The grams per second are right on.
Code 33 sets when flow exceeds 45 gps below 2k rpm and 1/4 throttle.
The ecm has a 5v pull-up on the signal wire. If the signal voltage is 2.2v or higher for 1 second code 33 will throw.
Is the fuel pump relay the odd bird of the 3 on the firewall by the brake booster ? I cleaned the other two matching relays when my 34 reared its head, I don't think I cleaned the third one. I also read it could be relay issues ? Those are $15 a pic, not terrible but this being intermittent makes me hesitant to buy a rebuilt $150 maf if the problem will still show up. I appreciate all you folks info and patience with me, I'm pretty excited the cars almost road worthy.
Never mind, I looked it and it appears it's one of the two I cleaned out but there appears to be 2 others that have to do with the maf that I didn't touch, I may try cleaning those...this thing sat for a long time, there's age gremilins galore.
a few weeks ago I had a code 34, but also found a massive vacuum leak on one of the intake runners so fixed that and car runs great. Then dealt with a code 42 and no spark advance...changed the icm and I have that fixed. Car was running great then dies, it fired a code 33 and wouldn't restart..unplugged the maf and it started up. I unplugged the batt to clear codes, restarted with maf plugged in and no code and it runs...check the scanner and gm/sec air at idle is 8, I rev up some and let it run and 5 min later the code comes back and it's barely running..gm/sec drops to 6, then 5 and it dies. I switched the maf before but figured the vac leak caused that code...I hate to go rebuy the maf again but I can't figure what else might cause this, it was running great and out of nowhere the code goes on and off with restarts.
Before I go buy this maf again I figured I'd ask for advice.
Thanks again,
i have found that in a lot of cases , the power and burn off relays are wrong / weak/ dead . that and the wiring going to and from the TPI . and i must point out that the MAF sensors on the market are of poor quality . and some fail right out of the box . i had good sucess with "rich porter " . but i cant find them anymore . the thing to stay FAR away from is the "cardone " and "airtex " POS . hope this helps
Thanks guys, I'm going to clean these relays up and see what happens, the only mafs I can find are those exact brands you named...I'd be really angry to spend that money and it not fix. I still have suspension, brakes, int. and paint on this thing. I'll def report back. The power and burn off relays are the far right two by the fender correct ? I have read a few diff posts on their location.
You can usually get a used 86-89 maf used in the classifieds for $50-60 or so.
I have programmed the code 33 threshold higher for guys running larger cams and a few people that can't get the error to go away. Hope it's a simple fix so you can move onto other things.
Thanks guys, I'm going to clean these relays up and see what happens, the only mafs I can find are those exact brands you named...I'd be really angry to spend that money and it not fix. I still have suspension, brakes, int. and paint on this thing. I'll def report back. The power and burn off relays are the far right two by the fender correct ? I have read a few diff posts on their location.
i wouldnt waste time cleaning relays . just make sure the right relays are in the right position. and yes , man is it ever hard to find a working MAF . makes me want to convert my 86 to speed density , and be done with all that BS
Excellent info ! I replaced the relays with new bw pcs from oreilly and ran a new iat sensor and rerouted to the air box, now that reads correctly and no more code 33. Now I'm on to brakes...thanks again for all your help.
12-31-2016, 06:33 PM
