The water pump, gasket, and thermostat are all brand new. Like a week old. Its not water pump related.

 

My truck was doing the same thing, finally found this slit in the outer wrapping under the rock guard wire on the fuel feed line. It was not leaking fuel but not allowing the proper fuel pressure and flow.

Runs great now!

 

I checked all fuel lines carefully.. everything is good. I sprayed csrb cleaner all around my intale and vacuum hoses.. no leaks apparent but i couldn't get to the back side of the lower intake... i suspect the gasket is bad there. I will be removing and checking/cleaning the iac. It is so strange. It will idle fine bu if the truck idles for more than about 1 minute the idle drops, but stays running. As soon as i give it gas however, it dies out, unless I feather the gas pedal untill it idles smooth.