My 03 Cummins with 98k miles just went down with error code indicating a lift pump problem. I replaced it and it seems to run fine, but the pump takes a long time to shut off. The shop manuel says that the pump should shut off after two seconds or if it needs priming it may stay on for up to 25 seconds. Does anyone know if the pressure sensor is internal to the pump or external, and should the pump be running that long. Advice anyone.?????