J H

Just replaced the MAF sensor on my 85. Now, sometimes upon start up, the service engine light will come on and the car will run rough. Checking the code shows code 33 (MAF). Once I check the code by jumping the proper pins at the ALDL terminal, the light goes out and the car will run great. If I do not reset the computer, the situation is OK. But, if I reset the computer, the same scenario will occur again after a short time. Any ideas as to what this problem could be?

85corvettec4

is that a low/high voltage detected code?

don hall

This link may have some helpful info (?):

http://www.corvettebuyers.com/c4vettes/maf.htm

J H

Thanks for the link. A faulty connection, as was stated in the article was being considered. I will look more into this right away. Thanks for the great article.

WW7

If you purchased a rebuilt maf sensor, then the sensor is probably so far off spec it's making the car run like crap...When my maf sensor failed, I went through 3 remanufactured units before I gave up trying to find a good one...It seems the companys that rebuild them don't bring them up to spec, they just rebuild them and send them out the door....I tell everyone, if they're going to use a rebuilt unit, they had better check there car with a scanner after putting it in because it can throw your air/fuel mixture off so far it can do damage to your engine..One of the rebuilt units I bought was so bad it wouldn't let the car start....WW

J H

I bought a new sensor. But, it is different design. Instead of having the fine wire, it has something that looks like a circuit boards. Seems much more durable that that thin wire, but I am not sure what else may be different. The car runs great -- as good as it ever has. it is just that I get the code 33 at times and runs rough. Check the code, restart the engine and everything is great -- for a while.

WW7

I really do think it would be a good idea to have your car hooked up to a scanner to check your Air/Fuel ratio.. If this is way off it can cause engine damage. Actually, anytime I replace a major engine component that is related to air/fuel I hook up my scanner to make sure nothing has changed...What may be happening is when you reset the code, the car runs off of the presets that are in your ECM, once the car goes into closed loop again and starts reading from the maf sensor you start having your problems with it running badly... WW

J H

Thanks. I will check this out right away.

FletchUSMC

I had pretty much the same luck with the MAF with the circuit board inside. You can search my old posts but sounds similar to your situation. If yours is still under warranty return it and go with the MAF with the wires inside. Might take a couple of them before you find one that works with your car.

vetteoz

http://www.chevythunder.com/maf_code_33.htm

WW7

Here are 2 threads from a few years ago when I had my maf sensor problems.. The first is showing the problem I had , the second is how I solved my problem......I don't know if you want to go to this extent or not, but it is a solution to the problem so you will never have to mess with it again..If you can find a good used maf sensor, that would be the best solution... Keep an eye on ebay , they have used maf sensors quite often......WW

http://forums.corvetteforum.com/c4-t...osch-dies.html

http://forums.corvetteforum.com/c4-t...-i-got-ww.html

J H

Thanks a million for all the replies. Excellent information. I will look into these suggestions and see what happens. Thanks.

Cliff Harris

That site isn't completely accurate because it doesn't mention that '85s have a MAF control module rather than the power and burnoff relays. The module does the same thing, just in a different way.