Engine Performance problem
1998 Other GMC Models V8 Four Wheel Drive Automatic 139000 miles

I own a 1998 GMC Suburban and am having a fuel delivery problem. The truck will start fine if cold, I run around town making a few stops and then the truck will not start again. I had the truck towed home and replaced the fuel pump with a factory unit based on the vehicle VIN #, I also replaced the fuel pump relay with a factory part and fuel filter. This is the second replacement fuel pump, previous pump lasted 2+years was also a factory replacement based on VIN# and the starter was also replaced at that time. With new pump it starts fine when cold but after running for 1/2 hour or 45 minutes I turned the truck off and when I went to start it 10 to 15 minutes later no fuel gettng to motor. I sprayed starter fluid in throttle body just to check it started but would not continue to run. A couple of hours later the truck starts and runs fine. I did notice the motor seemed to hesitate and almost stop but would catch and idle fine again after a couple of minutes. Need advice, Steve