i have a 2000 chevy truck with an ls1 5.3 the truck starts and runs for 30 seconds or so then ties and it does this over and over again. has fuel pres. and pump works

 

Welcome to the site. Although you have a truck and this is a car board, I suspect your issue may have some common cures. You have fuel pressure and the pump works, but is there flow? Could be a clogged fuel filter...

 

Do the trucks have an equivalent to Camaro's VATS security system? The symptoms sound similar to a worn VATS chip in the key.