I recently replaced the fuel pump in my 99 expy it has the 5.4. I noticed after I changed the fuel pump when I try to pass or get to freeway speed I punch the throttle the expy will get to a bout 60 mph and the engine will hit 3500 to 4000 rpm and stay they there. It will gain no more speed but will not slow down. When I back out of it it starts excelereating again. I checked the fuel pressure and found that I was getting 32 psi at Idle and when I removed the vaccum line from the regulator it bumped the pressure to 40 psi. I replaced the regulator but got no change. When I changed pumps I got the pump from NAPA which I also replaced the screen and filter. I would really appreciate and help you guys have to offer.