2001 surburban 5.3

I replaced the fuel pump awhile back, and had no problems for awhile I replaced harness and all with new fuel filter and fuel pump relay. After about 300 miles it stalled on me but restarted after a few minutes and I made it home, I thought water I refueled tank and added a fuel dryer. I went on a 200 mile trip and it stalled again would not start my passengers help push along with a couple police officers out of traffic after pushing The damn thing started, it cut out a couple times on the way home but it made it running 80 all the way. Today I went 12 miles to Walmart with no problems and picked up a throttle position sensor at advance auto on the way home, It stalled again would not restart I had my son bring my tools and replaced throttle sensor on the side of the interstate it started made it home. I then took it and ran it up and down the road checking it out but lord and behold it done it again I coasted in the driveway would not restart, I let it sit 30 minutes and the dam thing starts. I really like the truck but I am starting to remember why I have not own a chevy for so long LOL