I have 2 different EST laying around. One from and 88 z28 and the other from 92 Z28. The part numbers are different and the parts stores show the 88Z not interchangeable with the 92Z. Are they different or is this just number thing.

 

I have two ICM and one from a 88 Z28 and the other from 92Z28. Are the two ICM different or is it just the numbers listing. I have the 88 ICM in my 92 and the car just seems like its lacking power but not sure if the ICM is why.

 

From what I understand:

'88 is MAF, '92 SD. Shouldn't affect the ignition module.

'88 has separate knock sensor module, '92 has it built into the ECM. You said "EST", that's usually what the knock sensor module is also called - so there shouldn't be one for a '92.
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I answered the "EST" thread first, then found your ICM post.

Are these two different questions, or were you correcting yourself?

 

I was correcting my self. This is the part under the dist. cap.

 

Anyone? Accel list a different part number for 91 and 92 and so does GM but not the part store.