See Figures 1 and 2
- Unscrew the cap from the fuel rail pressure valve on the fuel rail. You may have to remove the fuel injector sight shield for access to the valve.
- Connect pressure gauge J-34730-1 or equivalent to the fuel pressure test point on the fuel rail. Wrap a rag around the pressure tap to absorb any leakage that may occur when installing the gauge.
Turn the ignition
; the fuel pump should run for a few seconds. Check the pump pressure for the following specifications:
- 1987-93 vehicles, except 1993 VIN K: 41-47 psi (284-323 kPa).
- 1993 VIN K and 1996-99 vehicles: 48-33 psi (333-376 kPa).
- Start the engine and allow it to idle. The fuel pressure should drop about 3-10 psi (21-69 kPa) due to the lower manifold pressure.
The idle pressure will vary somewhat depending on barometric pressure. Check for a drop in pressure indicating regulator control, rather than specific values.
- If the fuel pressure drops more than a few pounds when you shut the engine OFF , check the operation of the check valve, the pump coupling connection, fuel pressure regulator valve and the injectors.
- Before attempting to remove or service any fuel system component, it is necessary to relieve the fuel system pressure.
REMOVAL & INSTALLATION
See Figures 3 and 4
The fuel pump is located in the fuel tank. The fuel tank must be removed from the vehicle in order to access the pump.
- Properly relieve fuel system pressure.
- If not already done, disconnect the negative battery cable.
- Raise and safely support the vehicle.
- Safely drain and remove the fuel tank assembly, as outlined later in this section.
- If necessary, detach the quick-connect fittings from the fuel sender assembly and remove the fuel lines.
- Remove the fuel gauge sender and pump assembly by turning the cam locking ring counterclockwise. It may be necessary to use a spanner wrench, such as tool J-24187, to perform this.
- Carefully lift the assembly from the fuel tank, then remove the fuel pump from the fuel gauge sender unit.
- Remove the sender O-ring from the top of the sender and discard.
- Disconnect the pump wires, hose clamps and the clamp from around the pump body.
- Pull the pump assembly out of the rubber connectors.
- Inspect the fuel pump attaching hose for any signs of deterioration, and replace as necessary.
- Push the fuel pump assembly into the attaching hose. Attach the pump electrical wires and fasten the hose clamps to the attaching hose and around the pump body.
- Place the fuel tank sender and pump assembly into the fuel tank. Use a new O-ring seal during assembly.
- Place the cam lock over the assembly, then lock by turning clockwise, using a suitable spanner wrench, if necessary.
- If removed, attach the fuel sender fuel line quick-connect fittings.
When installing the fuel tank, make sure all rubber sound isolators or anti-squeak spacers are replaced in their original locations.
- Install the fuel tank, as outlined later in this section.
- Refill the fuel tank.
- Connect the negative battery cable.
- Turn the ignition switch to the ON position to pressurize the fuel system and check for leaks.