Start problem. I have read so many things about htis problem and still havnt fig it out . Here it is . I have a 91 mustang gt 5.0 all stock aod. When turning on ignition fuel pump runs continuesly and doesnt run its intial 5 to 20 second and cut off . The car has fire and fuel pressure injectors have 12 volts . I replaced the prssure reg and tried the relay but mine is 4 prong and the auto parts sells 5 prong . When i use the 5 prong the pump doesnt come one at all . I jump the wires where the fuel pump relay plugs in and the pump runs and the car startes but pump runs cont again . Only dif is the car starts . Please help.