Keep in mind that you have several components there:
- Fuel Pump Sender Assembly,
- Fuel Pressure Regulator,
- Fuel Rail Assembly, and
- Fuel Injectors.
1.- Fuel Pump (Sender Assembly) - TESTING
Refer to the accompanying charts for fuel pump diagnosis and testing.
The fuel injection system remains under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.Fig. 3.1L engine OBD system check to be done before fuel pump
relay circuit diagnosis
Fig. 3.1L engine fuel pump relay circuit diagnosis (1 of 2)
Fig. 3.1L engine fuel pump relay circuit diagnosis (2 of 2)
Fig. View of the fuel pressure test port (Schrader valve)-3.1L
A - 3.1L engine fuel system pressure test (1 of 4)B - 3.1L engine fuel system pressure test (2 of 4)C - 3.1L engine fuel system pressure test (3 of 4)D - 3.1L engine fuel system pressure test (4 of 4)Fig. The fuel pump/fuel sender module assembly is mounted in the
2.- Fuel Pressure Regulator - REMOVAL & INSTALLATION
(the fuel pressure regulator, which is
located on the fuel rail assembly)
NOTE: Before removing the fuel regulator assembly, place a clean
shop towel under the regulator to catch any fuel drips
Properly relieve the fuel system pressure.
If not done already, disconnect the negative battery cable.
On the 3.1L engine, remove the intake manifold plenum, as
On the 2.4L engine, remove the fuel rail. Refer to procedure
earlier in this section.
Detach the vacuum line from the regulator.
Place a shop towel under the regulator to catch any fuel that may
drip out. Unfasten the fuel pressure regulator retaining screw, then
remove the regulator by twisting and pulling it from the fuel rail.
Remove and discard the O-ring seal. Inspect the filter screen for
contamination and replace if necessary.
Prior to assembling the pressure regulator to the fuel rail,
lubricate the new rail-to-regulator O-ring seal with clean engine oil.
Place the O-ring on the pressure regulator and install the
pressure regulator to the fuel rail.
Install the retainer or coat the regulator mounting screws with an
approved thread locking compound and secure the pressure regulator in
place. Tighten the mounting screw to 76 inch lbs. (8.5 Nm).
If removed, install the fuel rail assembly to the engine.
The fuel return pipe must be connected before tightening the
regulator retaining screw to prevent the regulator from rotating.
Rotation of the regulator could damage the retainer and spacer bracket
and lead to a fuel leak at the regulator inlet.
Connect the fuel feed line and return line to the fuel rail
assembly, use a backup wrench on the fittings to prevent turning.
Attach the vacuum line to the regulator.
On the 3.1L engine, install the intake manifold plenum.
Connect the negative battery cable. Turn the ignition to
position for two seconds, then turn it to the
position for ten seconds. Turn again to the
position and check for fuel leaks.