I've heard that a MAF out of an '85 is different from the other years. Why and how do you tell the difference by looking at it?

 

Probably because their ECM is different than 86-89.

I'm not sure how to tell the difference physically though

 

I have a pic, but it doesn't seem to be online anymore. But anyway... the easiest way to tell the difference is by the screens. The 85 MAF has metal screens that aren't removable like on the 86-89 MAF. Each screen is sandwiched between plastic that's glued together. The only way to remove the 85 screens is to cut them out with a knife you don't mind butchering.

Anyway... an 85 MAF will work on the 86-89 cars, but the 86-89 style will not work properly on an 85. The 85 uses a pulsed a/c style output, and the 86-89 uses a DC voltage. The buffer on the 86-89 cars seems to be sufficient that it smooths out the pulses and results in a signal that's accurate enough for the 85 MAF to work. I still have the original MAF on my IROC which has been converted to the 165ECM and my MAF g/s numbers are right where they should be.

 

Hey thanx. I was just wondering b/c I'm getting a code 33 and thought it could be b/c the maf was an '85. I really don't want to have to buy a new one.

 

Why do you have a MAF on a 90 in the first place?

 

It used to be an L03 car....just like it says in my sig.