GMC Repair: 2000 Chevy Silverado Intermittent Cut Out, chevy silverado, guinea pigs

Question
We took it back to our mechanic. He repeatedly has hooked it up to his computer while idling or even in motion and apparently it picks up the cutting out but says nothing. Intially he did tons of basic stuff...tune ups, fuel filters, then he recommended a fuel pump. We replaced it, but the truck kept cutting out. Then he put another one on thinking it was faulty....it continued. He recommended an electrical guy check it out...the electrical guy saw the fuse box was melted...replaced the wire that was messed up next to it and the box and recommended another fuel pump and this time replace the pig tail. The truck seemed okay for a day...then continued to cut out. The electrical guy said to take it to a tranny expert as it seemed like a transmission problem. Our mechanic referred us to someone else.....replaced and continued to cut out. After looking for any TSBs or even recall's our mechanic then told us if it was his truck, he honestly would not sink any more money into it. He would wait for the truck to stop running...then he would surely find what was wrong. He said he had some ideas of what it could be, but at this point we would be guinea pigs and expensive ones at that...he was thinking along the lines of coil packs or even injectors.

A week later a guy at work tells me his Silverado did the same thing...he replaced the ignition switch and runs like a dream now. I told our mechanic, he said he had no problem doing it for us as a test, but he felt hard pressed to understand the correlation. The mechanic then told us he had an 2004 Chevy Silverado doing the same thing in his shop and the guy has replaced a lot of stuff already and nothing is fixing it. This friday the customer is returning because the customer wants the injectors replaced (even though he knows he is a guinea pig of sorts).

What do you think? I see you have another similar issues on a diesel, but this is a gas engine. Have you dealt with this before?

Answer
Yes I have seen this before, but it is very hard to diagnose without having the GM scan tool installed while driving it and seeing the data when it stalls. I have seen the Mass Airflow Sensor cause alot of the same problems. I have NEVER seen an injector or a coil on one of the Gen III motors cause it to stall. Also, GM has seen some Manifold Absolute Pressure Sensor failures that could cause stalling. It is possible that the ignition switch could cause it since it has a devoted leg for ignition. Also it wuold be interesting to drive it with a fuel pressure guage to see if you are actually losing fuel pressure when it stalls.

I must admit that I am sorry for your inconvenience, but I really would advise you to bring it to your local dealer. Mostly because if a GM Goodwrench dealer installs a fuel pump in your truck then you get a lifetime parts and labor warranty. Also, I know that my dealer would not allow us to continue to charge you or possibly to charge you at all if we did not fix your vehicle so I hope this has not cost you terribly.