how is the gas tank? im assuming you change the fuel filter before all of this? have you checked grounds on the engine and to the injectors, i know there is a place in the harness where the injectors are all spliced together and a spot on the harness where the injectors ground to the intake manifold. it is a must that you have a good ground to the injectors. i wouldnt always assume heat as the problem either. i would check your coil grounds and the coil itself with an ohm meter against the fsm specs too. like 4 crawler said try the easy (free) stuff first.... if your im doubt of the fuel pump you might try pulling it out and inspecting the tank and the sock for dirt... a dirty tank would coause a fuel pressure issue for sure....