Well, I'm loving my new truck but it has had a starting, and no power problem since I bought it a couple of weeks ago. The previous owner knew about the problem and even uad the fuel pressure regulator replaced in hope that it would fix the problem.
You can hear the fuel pump kick on and run for a few seconds when you turn the key on, but most of the time the truck will not start until the second attempt. It also feels like it has very little power on take off. If I let it sit for a few minutes after I shut it off and depress the Schrader valve on the fuel rail I get nothing. If I do it with the engine running then obviously I get fuel. Im thinking the check valve in the pump assembly is toast and not allowing any fuel pressure to remian in the line.
What do you guys think? Oh yeah, almost forgot. The fuel filter has been replaced also.

The truck is a 2003 Silverado 2500HD 4wd with a 6.0L and 5 speed manual.