Fuel Injector

A fuel injector is a solenoid valve that sprays fuel into the intake port or throttle body of a fuel-injected engine. The engine control unit (ECU) opens it for a precisely timed number of milliseconds, based on sensor readings for throttle position, rpm, air temperature and pressure, so the engine gets the right amount of fuel.

The fuel is pressurised by a pump in or near the tank and leaves the injector as a fine, atomised spray that mixes well with air. Some two-strokes and oil systems also use injectors for lubrication.

Dirty or clogged injectors cause rough idle, hesitation and poor fuel economy. Use fresh fuel, change the fuel filter as recommended and have injectors cleaned or flow-tested if problems appear.