Fuel injectors perform the same fundamental task as their carburetor predecessors — delivering fuel to combustion chambers — they just do it in a very different way.

Injectors are part of an electronic engine management system. An engine control unit (ECU) monitors inputs such as engine temperature, rotation speed, and performance demand to determine spark and the timing of fuel delivery. Injectors deliver fuel in precise amounts and specific spray patterns, either directly into cylinders or through a manifold or throttle body.

Injectors are very simple internally, featuring a solenoid and needle valve. Because the ECU decides when and how long that solenoid is opened, injectors don’t require adjustments to deliver the same amount of fuel in every situation.

Injectors allow the engine to start more consistently, run smoother, run cleaner, and in many ways can be easier and safer to tune in performance applications. But they are not exempt from maintenance considerations.