I have 150,000mile 1999 24 valve. I purchased in december and first thing i checked was lift pump, it was bad 0psi. I didn't know any better so I went to auto parts store and purchased a factory replacement one shaped different but worked. Now today was first time to put fuel and boost on truck and it shows 17-18 at idle and with cruising 2-3psi boost I am getting 15psi fuel. I laid into it in third gear and made 16psi boost and my fuel pressure went to about 8psi and jumped up as soon as i let off. Is this what everyone else is seeing? How about boost is 16psi top of third unloaded about all stock will do? Thanks guys. CD

With a medium truck rated engine in mine, I get 23 to 24 PSI at idle, and 13 to 14 PSI pulling a hill, pedal to the metal. I know it seems like a big drop, but you have to consider my MPG runs between 10 and 12 MPG.