🔍 Key Concepts

• Effect of air in high-pressure fuel lines on injection timing and fuel quantity • Relationship between fuel delivery and engine power/speed in a diesel engine • Typical causes and symptoms of loss of fuel pressure to injection nozzles

💭 Think About

• Think about what happens inside the cylinder if fuel is not delivered at the right pressure and in the right amount. • Which option best matches a situation where the engine is starved of proper fuel injection rather than getting too much fuel? • Consider what you would observe on the engine (speed, power, exhaust behavior) if air pockets interrupted the fuel flow to the injectors.

✅ Before You Answer

• Verify which options describe too much fuel versus too little or interrupted fuel. • Ask yourself: Does air in the lines increase or decrease effective fuel pressure at the injector? • Match the likely symptom: interrupted fuel injection will most directly show up as what change in engine operation?