Which condition would most directly cause a diesel engine to crank but not start?

• A. Dead battery
• B. Faulty fuel injector
• C. No fuel delivery
• D. Ignition switch failure

Answer: (C)

Diesel engines start by compressing air to heat it and then injecting fuel at the right moment so it ignites from that heat. If fuel never reaches the cylinders, there’s nothing to ignite, so the engine will crank but not start. That makes no fuel delivery the most direct reason for cranking without starting. Other issues like a dead battery would prevent cranking in the first place, a faulty fuel injector might cause hard starting or misfires but not necessarily complete fuel absence, and an ignition switch failure would stop the starter from turning. To diagnose, check fuel pressure and the fuel delivery path—pump, lines, and filters—to confirm fuel is reaching the cylinders.