Hey I got an 88 IROC w/ a 350 TPI. My chiltons says I should have one but it doensnt know exactly where it is. I certainly dont? Could someone tell me If I do or not and where it is? A local Parts store didnt list me even having one.... Hmm Thanks! - Tom

well if your car is stock then no you do not have one. they did not use them till 90 on the tpi f-body cars. you have a maf (mass air flow) sensor mounted before the throttle body.

Yep completely stock.... Well then how come the computer can throw like a code 33 which says some crap about the MAP sensor.



- Tom

Drekken,

Your Chitlin's manual is almost correct, and probably better than nothing at all. GM used the same DTC numbers for similar errors on different engines and fuel systems. A '33' on a TBI engine is different than a '33' on a TPI engine. A lot of the codes are used the same way. Because of the format used to display the errors, no "zeroes" can be used, since a "no flash" can't be counted as a "zero" (except on Cadillac digitals, and we won't go there right now).

For a complete listing of GM Diagnostic Trouble Codes through 1992, grab this file:

GM Error Codes.pdf

You'll need Adobe Acrobat Reader to open/view/print the file (see link below).

The '33' on your engine is for a MAF sensor that is reporting higher than expected intake air. This can be related to a TPS sensor or distributor reference pulse problem.

Thanks a lot. I'm going to check out the TPS and I do think im having ignition troubles. I'm gonna do plugs and wires because I dont think Its had a tune up in like 40k. I replaced the cap and rotor like a week ago. Thanks again!

- Tom

I just got one more question... I had my ignition module tested at a local Autozone.. and it tested fine. Do you think it could still be bad and cosing me some problems? Like it just needs time to start flaking out? And the HEI ? Thats the Ignition module isnt it?

Thanks!

Try replacing MAF relays on the fire wall.... usually the problem with MAF sensors... do that before replacing the MAF, since a relay is only like 20bux, where as a MAF is like 300bux...