Bad ECM, Have questions
 

Ok, does a ECM have to be replaced with a brand new one, or can a Used one be suplimented?

And then, is replacing a ECM something relatively easy, that I with limited mechanical knowledge acomplish, or is it better for a professional to do?

this is on my wifes 1994 Chevy S-10 Blazer Tahoe LT 4dr, with the 4.3L vortec. It also has the digi dash, if that makes a difference.

thanks.

RE: Bad ECM, Have questions
 

For your '91, you should only have to find a blazer with the same vin-digit/RPO-code as yours (VIN Z, RPO LB4). I don't think that anything else is stored in the ECM on this early of a vehicle so it should be a simple unbolt, unplug, and reverse.

RE: Bad ECM, Have questions
 

Swartlkk, I am so sorry. I forgot to add that this was for my Wife's 94 S-10 Tahoe LT. It has the 4.3L vortec.

the dealer was talking about needing the ECM to be flashed when it was replaced, and reprogramed with a electric scanner.

See, we had taken it to the Chevy dealer, and had it run through the diagnositc cycle or what ever they do...

anyway, it came back that the knock sensor said it was knocking all the time. It had retarded the timing, and she was chugging the fuel like a hobo finding a free bottle of whiskey.

anyway, they tested the knock sensor, it was good, and then then ECM came back bad. So, they want about 350 for the part, and 1 hour of labor. He offered me a 10% discount, and that would be about 490.... but I can't afford that, so I am looking for possibly the used route.