Misfire

[OkieMike]

My 2000 Silverado (4.3 Litre, 137k) is continung to misfire after several trips to my mechanic. Initialy, he informed me that there was a GM service bulletin for my problem which he said was an improperly machined valve guide...$1300 later, it's still misfiring. After I had the work done it was much better, but the problem continued. My mechanic said my plug wires were not in the best of shape and tried to reseat them a couple of times...the misfires continued. This weekend, I replaced the plug wires, distributor cap, and rotor(with quality replacement parts). After all this, it continues to misfire. I am extremely frustrated. (so is my mechanic)

Anyone out there ever heard of this service bulletin, or experienced anything similar? Any ideas?

Thanks,

OkieMike

[95CTburb19]

my friend had a 2000 EDIT: it was a 4.8l (sorry) that was misfiring and couldn't figure out why. He changed the plugs and found that the plugs in there were the original plugs with 125k and were gapped wayy to big. He got some new ones and now it runs great. Kind of simple, but it may be something you have overlooked.

[99Sub4x4]

The only misfire problems of the unusual kind (not wires, plugs, etc.) on this engine was the spider injector. Had a mechanic friend who bought a new S10 and narrowed it down to the spider injector. It was pinched off at the factory!