Which component is necessary for diesel engines to inject fuel into the combustion chamber?

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

Answer: (C)

Diesel engines rely on compression ignition, so fuel must be delivered directly into the hot, compressed air in the cylinder at the right time and in precise amounts. The device that does this is the fuel injector, which meters and sprays fuel under high pressure to ensure proper combustion. A carburetor blends fuel with air before it enters the engine and is used on many gasoline engines, not diesels. A magneto or ignition coil is part of the spark-ignition system and provides a spark to ignite the mixture—diesels don’t use a spark, they ignite by heat from compression, so those parts don’t inject fuel.