1998 Silverado 2500 on cranking during start dies immediately after it lights off. It's my neighbors truck. He said it happened previously and he let it sit for 15 minutes and it started normally. I put a fuel pressure gauge on it and when the key is on, it read 61 psi. Had him try to start it and it started right up. Fast forward to yesterday. He was stranded after it did the same thing again. He had it towed last night. Any and all suggestions are welcome, thanks!