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