HI ALL! I have a 2000 Silverado 4.8 Liter v8 manual transmission with 103,000 miles. Back in October, I replaced the fuel pump. I replaced it in an effort to save over 500 dollars from the mechanic. I bought the pump from Napa instead of Carquest (AC Delco parts) in an effort to save an additional 150 dollars. I also replaced the fuel filter just prior to installing the fuel pump. At the time I also replaced the spark plugs, and gapped them properly before installation. I did not replace the spark plug wires. In addition I replaced the battery and the front 2 O2 sensors. What's happening now, which has been going on for about the last 2 months. Every morning, it fires up like a brand new truck. I drive about 4 miles to work, and by noon it doesn't want to start. It will turnover, but the fuel delivery is not there. It takes about 10 seconds for the engine to turn over. What I've done so far, I bought a fuel pressure gauge and it reads 58psi w/ the key turned and the engine off, and once started it sits at 50psi consistently. I looked through the threads and couldn't find a similar problem, but if anyone can provide some insight - I sure would appreciate it!!!