1997 GMC Truck 1997 GMC 1500 4X4

I have a 1997 gmc 1500 with a 5.7 liter vortec. It runs fine when the engine is cool. When the engine warms up it starts to cut out when accelerating lightly. Also when you set the cruise it cuts out about every 5 seconds especially when you start to go up and incline. When starting the truck after it had been running awhile, when the motor is up to temp its hard starting. It starts as if its not getting enough gas and it sets there spittin and sputtering. When it rains it runs even worse. It seems to do more of a backfire instead of cutting out when it rains. Iv replaced the fuel pump, got new plugs and wires and a new coolant temperature sensor in the last 3 or 4 months. I dont know what it is I need help.