Quote Originally Posted by jick.cejoco View Post
you're saying that it can crank normally but fails to start? start by checking the voltage to the fuel shut off solenoid at the injection pump. if it does not have battery voltage (maybe lower or none at all at times), check the wiring and the fuse. if it does have voltage, check by listening with a stethoscope or suitable material to listen to the solenoid operation. you should hear a metallic click when the ignition switch is switched on
+1 here. I experienced the fuel cut solenoid valve not engaging because the voltage to the terminal dropped to around 10v resulting to the engine still cranking (since most diesels use reduction gear starters) but not starting. Charging the battery solved the problem (battery got discharged when vehicle was left for more than 2 weeks with the door ajar and the door courtesy lamps left on).

If your voltage is normal but the fuel cutoff solenoid (Circuit brand names it "shut off valve") still won't engage despite its terminal having the correct voltage, then either your engine grounding is poor or the valve itself needs replacement.