🔍 Key Concepts

• Fuel pump rack function and how it controls fuel quantity to each cylinder • Why diesel engine adjustments like rack setting are normally done with the engine secured for safety and accuracy • How a master pump (or reference pump) is used to match the settings of individual fuel pumps on multi-cylinder engines

💭 Think About

• From the illustration, is the fuel pump rack something you would want to expose while high-pressure fuel is being delivered, or when the engine is stopped? • When checking whether an individual pump’s rack is correctly set, do you need something to compare it to, or is simply looking at it enough? • Which procedures in the choices would realistically be used in a shop manual to ensure all pumps deliver the same amount of fuel?

✅ Before You Answer

• Eliminate any choice that requires removing covers with the engine running at speed under high-pressure fuel—consider personal and equipment safety. • Ask whether the procedure includes a way to compare each pump’s rack position to a standard or master reference. • Make sure the step sequence is logical: secure engine first, then remove covers, then check/adjust settings rather than the other way around.