Dodge dakota 2002 Service Manual page 1729

14 - 32 FUEL INJECTION - GAS
FUEL INJECTOR
DESCRIPTION
An individual fuel injector (Fig. 17) is used for each
individual cylinder.
Fig. 17 FUEL INJECTOR
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
OPERATION
OPERATION - FUEL INJECTOR
The top (fuel entry) end of the injector (Fig. 17) 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, add-
ing it to the air entering the combustion chamber.
The nozzle (outlet) ends of the injectors 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 sequen-
tial 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.
OPERATION - PCM OUTPUT
The nozzle ends of the injectors are positioned 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 with its
respective cylinder number.
The injectors are energized individually in a sequen-
tial 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 (12 volts +) is supplied to the injec-
tors through the ASD relay. The ASD relay will shut-
down the 12 volt power source to the fuel injectors if
the PCM senses the ignition is on, but the engine is
not running. This occurs after the engine has not
been running for approximately 1.8 seconds.
The PCM determines injector on-time (pulse width)
based on various inputs.
REMOVAL
(1) Remove fuel rail. Refer to Fuel Injector Rail
Removal.
(2) Disconnect clip(s) that retain fuel injector(s) to
fuel rail (Fig. 18).
Fig. 18 INJECTOR RETAINING CLIP
1 - PLIERS
2 - INJECTOR CLIP
3 - FUEL INJECTOR - TYPICAL
4 - FUEL RAIL - TYPICAL
DR