Starts cold runs great... but not when warm
 

I have a 2000 Silverado 4x4 4.3 vortec, it starts fine cold, but after running will turn over but not fire. New injectors, CPS, EGR, ICM, Dist cap and rotor, plugs and wires, starter, fuel pump. Runs great no timing issues when it does start. t has 324,000K on It mostly highway. Any suggestions? I love this truck