Dodge Durango

 Service Manual

Fuel System » Fuel delivery system » Description and operation
Fuel injectors

DESCRIPTION

An individual fuel injector (Fig. 4) is used for each individual cylinder.

Fig. 4 Fuel Injector-Typical

1 - FUEL INJECTOR

2 - NOZZLE

3 - TOP (FUEL ENTRY)

OPERATION

The top (fuel entry) end of the injector (Fig. 4) 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 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.

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.

Pcm vin reprogramming

Fuel delivery system

Fuel pump module

Fuel pump

Fuel gauge sending unit

Fuel filter/fuel pressure regulator

Fuel tank

Fuel injectors

Fuel rail-3.9/5.2/5.9L engines

Fuel injector rail-4.7L engine

Fuel tank filler tube cap

Fuel tubes/lines/hoses and clamps

Quick-connect fittings