Dodge Nitro. Manual — part 679

Fig. 92: Identifying CKP Sensor, O-Ring & Mounting Bolt
Courtesy of CHRYSLER LLC

1. Clean out machined hole in engine block.

2. Apply a small amount of engine oil to sensor o-ring (3).

3. Install sensor (2) into engine block with a slight rocking and twisting action.

1 - MOUNTING BOLT
2 - CKP SENSOR
3 - O-RING

CAUTION: Before tightening sensor mounting bolt (1), be sure sensor is

completely flush to cylinder block. If sensor is not flush, damage to

2007 Dodge Nitro R/T

2007 ENGINE Fuel System - Nitro

4. Install mounting bolt (1).

5. Connect electrical connector to sensor.

6. Lower vehicle.

INSTALLATION - 4.0L

Fig. 93: Identifying CKP/Oxygen Sensors - 4.0L
Courtesy of CHRYSLER LLC

1. Clean out machined hole in transmission bellhousing.

2. Install sensor (6) into transmission.

3. Install mounting bolt (5).

4. Connect electrical connector to sensor.

5. Lower vehicle.

INJECTOR-FUEL

DESCRIPTION

FUEL INJECTORS

sensor mounting tang may result.

CAUTION: Before tightening sensor mounting bolt (5), be sure sensor is

completely flush to transmission. If sensor is not flush, damage to
sensor mounting tang may result.

2007 Dodge Nitro R/T

2007 ENGINE Fuel System - Nitro

Fig. 94: Identifying Injector Body, Fuel Outlet Nozzle & Fuel Inlet Nozzle
Courtesy of CHRYSLER LLC

An individual fuel injector (1) is used for each individual cylinder. See Fig. 94.

OPERATION

FUEL INJECTORS

The top (fuel entry) end of the injector is attached into an opening on the fuel rail. See Fig. 94.

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

1 - INJECTOR BODY
2 - FUEL OUTLET NOZZLE
3 - FUEL INLET NOZZLE

2007 Dodge Nitro R/T

2007 ENGINE Fuel System - Nitro

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.

FUEL INJECTORS - 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 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 (12 volts +) is supplied to the injectors 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

FUEL INJECTORS

2007 Dodge Nitro R/T

2007 ENGINE Fuel System - Nitro