Diesel engines require:

• A. A carburetor
• B. A magneto
• C. A fuel injector
• D. An ignition coil

Answer: (C)

Diesel engines rely on compression ignition, which means fuel must be metered and injected directly into the highly compressed hot air in the cylinder. That requires a fuel delivery system capable of injecting fuel at high pressure and precisely timed with the piston position. A fuel injector performs this role, atomizing and delivering the exact amount of fuel at the right moment.

A carburetor mixes air and fuel before intake, which isn’t compatible with diesel operation that depends on compression heat to ignite the fuel. A magneto or an ignition coil provides a spark in spark-ignition engines, but diesels don’t use a spark to ignite the fuel, so those aren’t required.