What do I do next?

[Cdshinne]

My 2000 5.3 has trouble starting especially when it is warm out. This is going to be hard to word but im going to do the best i can. The starter turns the motor over fine and is strong. When i hit the ignition i could hold it forever and it wont start, the starter turns the motor over fine but wont fire. If i bump it once then hit it again it fires well sometimes it takes 3 or 4, the hotter it is out the worse it is. When it is below freezing out it fires right up and the motor runs better in the colder weather also.

This has been pissing me off for a while and i have a new fuel pump, fuel regulator, fuel filter, plugs, and wires, whats next? Any help would be great!

Thanks, Chad