INJECTOR-FUEL
DESCRIPTION
An individual fuel injector (1) is used for each individ-
ual cylinder.
OPERATION - FUEL INJECTOR
The top (fuel entry) end of the injector (3) is attached
into an opening on the fuel rail.
The fuel injectors are electrical solenoids. The injector
contains a pintle that closes off an orifice at the nozzle
end. When electric current is supplied to the injector,
the armature and needle move a short distance
against a spring, allowing fuel to flow out the orifice.
Because the fuel is under high pressure, a fine spray
is developed in the shape of a pencil stream. The
spraying action atomizes the fuel, adding it to the air
entering the combustion chamber.
The nozzle (outlet) ends of the injectors (2) are posi-
tioned into openings in the intake manifold just above
the intake valve ports of the cylinder head. The engine
wiring harness connector for each fuel injector is
equipped with an attached numerical tag (INJ 1, INJ 2 etc.). This is used to identify each fuel injector.
The injectors are energized individually in a sequential order by the Powertrain Control Module (PCM). The PCM will
adjust injector pulse width by switching the ground path to each individual injector on and off. Injector pulse width is
the period of time that the injector is energized. The PCM will adjust injector pulse width based on various inputs it
receives.
Battery voltage is supplied to the injectors through the ASD relay.
The PCM determines injector pulse width based on various inputs.
14 - 30
FUEL INJECTION
ND