About 10 years ago, I had my fuel pump replaced by a shop. Not long after, I would randomly get a not start condition (motor would turn over strong, but no start). I took the truck back to the shop that did my fuel pump. The mechanic reached up over the tank and jiggled the connector to the fuel pump. Started working ok...for a while. Eventually the random no start condition returned. I could get it going by laying under the tank and reaching up and jiggling the connector to the fuel pump. I put up with this crap for a while till I got fed up, dropped the tank and replaced the damn connector (wiring harness side). Problem solved. I changed my fuel pump since then (proactively, because the damn thing was so noisy and it was 10 years old). This time I made sure to buy the AC delco pump that came with a replacement connector for the harness side. No problems since. And the pump is nice and quiet!