Can anyone tell me the limits of the Lbz fuel pressure sensor? I have an Lbz that will not start. Upon diagnostics I found the rail pressure is reading a steady 71psi when ignition is on and when cranking....It doesn't move at all...When the sensor is unplugged it reads 29k~...I am thinking I have a bad sensor ...Not showing pressure and not allowing the ECM to fire the injectors? Most all other Duramax's show 200-250psi when sitting with engine off