I got an 86 IROC TPI, and I am getting a code 33, by the info I read it sounds like a problem with the MAF (Mass Air Flow), anyone got any insight into this, and does anyone know how to test the MAF to see if it is defective.

 

Clear the codes. If it comes back, connect a digital tach (use 4-cylinder scale) to the yellow signal wire at the MAF (leave the MAF plugged in). Key ON, engine OFF.

If the tach reads more than 4000 RPM, replace the MAF. If it reads less than 4000 RPM, the problem is intermittent. In either case, you'll probably end up replacing the MAF anyway.

You'll need something like this:

http://www.amazon.com/gp/product/B0002LZU7K

EDIT: Oops. The above if for a Delco MAF and not a Bosch MAF. I'll have to do some digging and get back to you.

 

This should help.

 

Gotcha thanks for the info, Im not sure which brand it is, I think its something other than those two though, I got it bout 5 years ago at advanced auto parts, but it was a factory like replacement type, so would that make it like a AC delco one

 

You will get a 33 error code if the following three items are true at the same moment in time:
1) ECM reads 45 gms/sec or higher from the MAF,
2) TPS is less than 1/4 throotle (whatever this actually means?),
3) Engine RPM is less than 2,000.

Us guys with modified 350s get this code often. The only way that I could get rid of the 33 code was to burn an Eprom chip. I did this after trying every thing else, like change the MAF and change the relays.

If your MAF is bad and that it outputs more than 45 gms/sec all the time, you should set the 33 error code eventually by meeting the three conditions above.