I am going to post what i know about the pickup as it's not mine but my father inlaws. Its an 01 with 5 speed 3/4 ton. He says that it may run fine for hours or just minutes and then it will act like it is getting no fuel as you can floor it with no change, but you can mash the clutch at speed (70) and let engine go to idle and it will take off like a scalded cat again. Has some form of power chip and an exhaust brake, but i can't see either of these causeing this problem or am i over looking something. Have read alot about the lift pumps goin bad, and this might explain why if it goes to idle it will catch up so how and where do i hook up a pressure gauge to check the lift pump? Thanks for any input in advance