jcsereiko

i have gone through two used maf and three remanufactured maf. i replaced the maf burnoff relay and the other relay next to it on the fire wall. tha maf harness is fairly new and so is the pig tail. i tried to wiggle it when the car was running to see if it was a bad connection. the computer has also been replaced with a remanufactured one. i have 62,000 orig miles on the iroc on the light is driving me crazy. it goes on about 4 seconds after the car is started. the car seems to run ok . any ideas whaT THIS PROBLEM IS.

1987IROC350

Faulty or disconnected vacuum hoses.

Faulty or loose wiring and/or connections at the ECM.

Faulty MAP sensor.

The code is a general "LOW VACUUM SENSED". So I'd check the above plus hoses. What engine do you have????? That should help members to identify possible vacuum problems.

jcsereiko

it is a 89 5.0 iroc z28 auto TPI with 62,000 orig. miles . in 1989 they did not have a map sensor for this year for some reason. the code 33 means low volts. i had a chevy manual from the dealer and it has nothing to do with vaccum because their is not a map set up on a 89 TPI. i wish they did because that would make it easy since i have replaced everything else. i'm up for any other suggestions. this light is driving me crazy

1987IROC350

Click on the link and scroll down to code 33. It states the code is good for '89 and earlier. All info I find says the same thing. Good luck.
http://www.iroc-z.com/1988pages/1988factsandfigures.htm

IROC-T

Gee thats strange, the only MAP sensor my '88 has is the one going to my Boost gauge(not stock). MY book says 33 is for the MAF. Try wingling the connector at the firewall down under the brake booster, that cleared up my three year 34 code problem.

RedIrocZ-28

What you'll ideally want to do is get yourself a voltmeter and test out the voltage coming out of the MAF sensor, If it stays the same no matter how much throttle you give it, then there is a problem with the MAF. But since you've already tried this multiple times I can't see it being the problem. Its likely that its a grounded wire in the harness, maybe the casing rubbed through on a sharp metal surface OR it could be a broken wire inside the casing leaving it out of view.

Conversely, I would like to pose a question. Do you have a modified engine? If so, I seem to recall a code 33 before I got it tuned correctly with the Low Volt diagnostic MAF reading or whatever it was. Had to raise it up or the intake reversion at low RPM's sometimes fooled the MAF into thinking less air was entering because of some air blowing back through the MAF.

jcsereiko

it states all except 89 and earlier . I am 100% positive that my car has no map sensor. for some reason GM did not put a MAP sensor on the 89 TPI CAMARO. thanks for the info , but it was info for 88 models and i know what it says about the 89 but that info. is not correct. there is not a map sensor on the 89 camaor iroc tpi maf.

jcsereiko

thanks, i will try that. it sound like it might work.