My buddy has a 1997 4.3L blazer 4x4. He's had a lot of demons for some time now, and has not been able to find the problem. THe most current list of symptoms are: Car runs fine intermitently, and runs in limp home mode. WHen it runs fine, it has a CEL, and he pulled the codes and got back 7 or so things wrong. He's replaced some parts, and still gets the same codes. He currently thinks the computer is bad. We checked at the local Shucks (Kragens) and they want $125 and the computer has to be programmed (by dealer?) based on the VIN. Napa wants around $200 for a computer and they will program it at thier warehouse.

I told him that it might be bad connectors on the computer end of the engine harness, or it might be bad grounds.

My questions are:
Are these computers known to be unreliable?
Do poeple end up replacing them often?
If you got 7 codes at once, does that point to a bad computer?

I am trying to save him a few bucks. I would hate for him to spend $200 and find the problem not fixed. Unfortunately (for him) Idon't havemany computer related problems with my own cars, so I only have experience diagnosing my MR2 turbo when I bumped up the horsepower.

 

Well I would list those codes, these trucks are not known for bad ECMs at all. One code could actually trip others as well. Also a vacuum leak can trip many codes too. So list those codes, and lets see what we can find out for you.