🔍 Key Concepts

• Fuel system restrictions vs. timing problems in diesel engines • Effect of fuel quantity and flow on engine speed and ability to take load • How injection timing and compression pressure usually show up (hard starting, knocking, smoke)

💭 Think About

• If an engine will start and fire, but won’t reach normal RPM even with little or no load, what would limit how much fuel can actually get to the cylinders? • Which option would more likely cause hard starting, knocking, or rough running rather than just low maximum speed? • Think about which problem would get worse as you increase load, and is directly related to fuel flow to the engine.

✅ Before You Answer

• Compare symptoms of fuel starvation/restriction vs. timing issues in a diesel engine • Decide which options mainly affect how much fuel reaches the engine, not just when it is injected • Ask: which condition is most directly like partially closing the fuel supply valve — limiting speed but still allowing the engine to start and run?