[Captain Planet]

My 2000 suburban did the same thing 2 years ago. It might be your fuel pressure regulator. It is located on the driver side of the fuel rail. When it fails it lets fuel leak out of the line and it goes into your engine flooding the engine and making warm starts hard. Cold starts are easy because the fuel leaked into the engine has had a chance to evaporate. If your shutting off your truck and the pressure is falling, this may be a sign of a bad regulator. Also, I had a gasoline smell around the engine. I almost forgot, there is a small vacuum line that comes off the regulator, if you pull that off and it is full of gas, the regulator is bad. It is about a $70 part if I recall correctly.

Good luck.