I am getting 56-58psi at idle but as i accelerate the fuel pressur will drop below 20psi and the truck canbarely go over 40-50mph. If i lift off the throttle the pressure will build again but once I press the pedal it drops again. The fuel pump started whinning pretty loud so I thought it was the fuel pump. I just put in the new FORD fuel pump assy and it still does it. What else can cause this pressure drop? The new pump whines also but not as loud as the one I replaced. Could I have a bad new fuel pump?