Fuel Injector: Description and Operation

Fuel Injector:

PURPOSE
Fuel injectors spray highly atomized fuel into the intake system to promote complete combustion of the air/fuel mixture.

LOCATION
Injectors are located on the intake manifold, near the cylinder head mating surface.

CONSTRUCTION
The injector is constructed of a metal housing containing a magnetic solenoid operated pintle. The injector inlet houses a fine mesh screen to filter out foreign particles. Top and bottom O-rings seal the outside of the injector to the intake manifold and fuel rail.


OPERATION
When the engine is cranking or running, constant voltage is supplied to the positive side of the solenoid valve from the fuel injection relay. The ECU grounds the solenoid valve to complete the circuit, energizing the magnetic winding and raising the injector pintle. When the pintle is raised, pressurized fuel sprays through a metered orifice into the intake system.