2. A system which injects fuel into an engine and includes an electronic control unit to time and meter or measure the flow.
Fuel is delivered in intermittent pulses by the opening and closing of solenoid-controlled injectors.
The fuel injectors are valves that, at the appropriate times, open to allow fuel to be sprayed or atomized into a throttle bore or into the intake manifold ports.
The fuel injectors are usually solenoid operated valves under the control of the vehicle's on-board computer resulting in "electronic fuel injection".
The fuel efficiency of fuel injection systems is less temperature-dependent than carburetor systems. Diesel engines always use injectors.