Not sure what's wrong w the truck. I think my mechanics are scratching their heads too. Just changed cap and rotor 3 months ago. Was hard starting and so changed the starter a month ago or less. Now dies in reverse (right after we changed the starter) and chugging on the highway at 45mph or higher. Works better when warm. Relatively new fuel pump(4 yrs). Don't wana throw a bunch of parts at it. Help.