Файл: 92FWD_14.pdf

14 - 130 FUEL SYSTEMS

FUEL SYSTEM PRESSURE RELEASE PROCEDURE

The 3.0L MPI fuel system is under a constant pressure of approximately 330 kPa (48 psi). Before servicing the fuel pump, fuel lines, fuel filter, throttle body or fuel injectors, the fuel system pressure must be released.

(1)Loosen fuel filler cap to release fuel tank pres-

sure.

(2)Disconnect injector wiring harness from engine harness (Fig. 3).

(3)Connect a jumper wire between terminal Number 1 of one injector harness and engine ground.

(4)Connect a jumper wire to the positive terminal Number 2 of the injector harness and touch the battery positive post for no longer than 5 seconds. This releases system pressure.

(5)Remove jumper wires.

(6)Continue fuel system service.

Fig. 3 Injector Harness Connector

THROTTLE POSITION SENSOR

REMOVAL

(1)Disconnect negative cable from battery.

(2)Remove electrical connector from throttle position sensor.

(3)Remove throttle position sensor mounting screws (Fig. 4).

(4)Lift throttle position sensor off throttle shaft.

Fig. 4 Servicing Throttle Position Sensor

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INSTALLATION

(1)Install throttle position sensor on throttle shaft. Install mounting screws. Tighten screw to 2 NIm (17 in. lbs.) torque.

(2)Connect electrical connector to throttle position sensor.

(3)Connect negative cable to battery.

AUTOMATIC IDLE SPEED (AIS) MOTOR

REMOVAL

(1)Disconnect negative cable from battery.

(2)Remove electrical connector from automatic idle speed (AIS) motor.

(3)Remove AIS motor mounting screws (Fig. 5).

Fig. 5 Servicing Automatic Idle Speed Motor

(4) Remove AIS motor from throttle body. Ensure the O-ring is removed with the AIS motor.

INSTALLATION

(1)The new AIS motor has a new O-ring installed on it. If pintle measures more than 1 inch (25 mm) it must be retracted. Use the DRB II AIS Motor Open/Close Test to retract the pintle (battery must be connected.)

(2)Carefully place AIS motor into throttle body.

(3)Install mounting screws. Tighten screws to 2 NIm (17 in. lbs.) torque.

(4)Connect electrical connector to AIS motor.

(5)Connect negative cable to battery.

FUEL INJECTOR RAIL ASSEMBLY

REMOVAL

WARNING: THE 3.0L MPI FUEL SYSTEM IS UNDER A CONSTANT PRESSURE OF APPROXIMATELY 330 KPA (48 PSI). PERFORM FUEL PRESSURE RELEASE PROCEDURE BEFORE SERVICING THE FUEL RAIL OR FUEL INJECTORS.

(1) Perform the Fuel Pressure Release Procedure.

Fig. 6 Throttle Cable Attachment

(5)Disconnect electrical connectors from the automatic idle speed (AIS) motor and throttle position sensor (TPS).

(6)Remove vacuum hose harness from throttle body (Fig. 7).

(7)Remove vacuum hoses from air intake plenum (Fig. 7).

Fig. 7 Electrical and Vacuum Connection to Throttle Body

(8)IF equipped with EGR, remove the EGR tube flange from intake plenum (Fig. 8).

(9)Remove the wiring connector from the coolant temperature sensor (Fig. 9).

(10)Remove vacuum connections from air intake plenum vacuum connector (Fig. 9).

(11)Remove fuel hoses from fuel rail (Fig. 9).

(12)Remove air intake plenum to intake manifold mounting fasteners (Fig. 10).

(13)Remove ignition coil.

(14)Remove air intake plenum (Fig. 11).

Fig. 8 EGR Tube to Intake Plenum

Fig. 9 Coolant Temperature Sensor

Fig. 10 Air Intake Plenum to Intake Manifold Attaching Fasteners

(15)Cover intake manifold while servicing injector fuel rail (Fig. 12).

(16)Remove vacuum hoses from fuel rail (Fig. 12).

Fig. 11 Removing Air Intake Plenum

Fig. 12 Vacuum Connections at the Fuel Rail

(17) Disconnect fuel injector wiring harness from engine wiring harness (Fig. 13).

Fig. 13 Fuel Injector Wiring Harness

CAUTION: Do not damage the injector O-Rings when removing the injectors and fuel rail assembly..

(18) Remove fuel rail mounting bolts. Lift fuel rail assembly off of intake manifold.

INSTALLATION

(1)Be sure injectors are seated into the receiver cup with lock ring in place.

(2)Make sure the injector holes are clean and all plugs have been removed.

(3)To ease installation, lubricate injector O-ring with a drop of clean engine oil.

(4)Put the tip of each injector into their ports. Push the assembly into place until the injectors are seated in the ports.

(5)Install fuel rail attaching bolts. Tighten bolts to 13 NIm (115 in. lbs.) torque.

(6)Install fuel supply and return tube holddown

bolt and the vacuum crossover tube holddown bolt. Tighten bolts to 10 NIm (95 in. lbs.) torque.

(7)Connect fuel injector wiring harness to engine wiring harness.

(8)Connect vacuum harness to fuel rail assembly.

(9)Remove covering from lower intake manifold and clean surface.

(10)Place intake manifold gaskets with beaded sealer up on lower manifold. Put air intake in place.

Install ignition coil. Install attaching fasteners and tighten to 13 NIm (115 in. lbs.) torque.

(11)Connect fuel lines to fuel rail. Tighten hose clamps to 1 NIm (10 in. lbs.) torque.

(12)Connect vacuum harness to air intake plenum and fuel pressure regulator.

(13)Connect coolant temperature sensor electrical connector to sensor.

(14)Connect EGR tube flange to intake plenum. Tighten mounting nuts to 22 NIm (200 in. lbs.) torque.

(15)Connect PCV and brake booster supply hose to intake plenum.

(16)Connect automatic idle speed (AIS) motor and throttle position sensor (TPS) electrical connectors.

(17)Connect vacuum vapor harness to throttle

body.

(18)Install throttle cable.

(19)Install air inlet hose assembly.

(20)Connect negative cable to battery.

CAUTION: When using the ASD Fuel System Test, the Auto Shutdown (ASD) Relay remains energized for either 7 minutes, until the test is stopped, or until the ignition switch is turned to the Off position.

(21) With the ignition key in ON position, access the DRB II ASD Fuel System Test to pressurize the fuel system. Check for leaks.

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FUEL PRESSURE REGULATOR SERVICE

REMOVAL

WARNING: THE 3.0L MPI FUEL SYSTEM IS UNDER A CONSTANT PRESSURE OF APPROXIMATELY 330 KPA (48 PSI). PERFORM FUEL PRESSURE RELEASE PROCEDURE BEFORE SERVICING THE FUEL PRESSURE REGULATOR.

(1)Perform the Fuel Pressure Release Procedure.

(2)Disconnect negative cable from battery.

(3)Loosen fuel return hose clamp and remove fuel return hose from nipple.

(4)Remove vacuum hose from fuel pressure regulator. (Fig. 14)

(5)Remove screw holding fuel return tube to the intake manifold.

(6)Remove fuel pressure regulator screws. Remove fuel pressure regulator from engine.

Fig. 14 Fuel Pressure Regulator

INSTALLATION

(1)Lubricate O-ring on fuel pressure regulator with clean 30 weight engine oil.

(2)Install fuel pressure regulator into fuel rail. Tighten screws to 10 NIm (90 in. lbs.) torque.

(3)Install screw holding fuel return tube clamp in place. Tighten screw to 10 NIm (95 in. lbs.) torque.

(4)Connect vacuum hose to fuel pressure regulator.

(5)Connect fuel return hose to fuel return tube. Tighten hose clamp to 1 NIm (10 in. lbs.) torque.

(6)Connect negative battery cable.

CAUTION: When using the ASD Fuel System Test, the Auto Shutdown (ASD) Relay remains energized for either 7 minutes, until the test is stopped, or until the ignition switch is turned to the Off position.

(7) With the ignition key in ON position, access the DRB II ASD Fuel System Test to pressurize the fuel system. Check for leaks.

FUEL SYSTEMS 14 - 133

FUEL INJECTORS

WARNING: THE 3.0L MPI FUEL SYSTEM IS UNDER A CONSTANT PRESSURE OF APPROXIMATELY 330 KPA (48 PSI). PERFORM FUEL PRESSURE RELEASE PROCEDURE BEFORE SERVICING THE FUEL INJECTORS.

REMOVAL

(1)Perform the Fuel Pressure Release Procedure.

(2)Disconnect negative cable from battery.

The fuel rail must be removed first to service the injectors. Refer to Fuel Injector Rail Assembly Removal in this section.

(3)Label each injector connector with its cylinder number. Disconnect electrical connector from injector.

(4)Position fuel rail assembly so that the fuel injectors are easily accessible.

(5)Remove injector clip from fuel rail and injector (Fig. 15).

Fig. 15 Fuel Injector and Rail

(6)Pull injector straight out of fuel rail receiver cup (Fig. 16).

(7)Check injector O-ring for damage. If O-ring is damaged, it must be replaced. If injector is to be reused, a protective cap must be installed on the injector tip to prevent damage.

(8)Repeat procedure for remaining injectors.

INSTALLATION

(1) Before installing an injector, the rubber O-ring must be lubricated with a drop of clean engine oil to aid in installation.