Grand Cherokee 2WD V8-5.2L VIN Y (1998)
4. Start engine and bring to normal operating temperature.
5. Observe test gauge. Normal operating pressure should be 339 kPa +/- 34 kPa (49.2 psi +/- 5 psi).
6. Shut engine off.
7. Pressure should not fall below 30 psi for five minutes.
8. If pressure falls below 30 psi, it must determined if a fuel injector, the check valve within the fuel pump module, or a fuel tube/line is leaking.
9. Again, start engine and bring to normal operating temperature.
10. Shut engine off.
11. Testing for fuel injector or fuel rail leakage: Clamp off the rubber hose portion of Adaptor Tool between the fuel rail and the test port "T" on
Adapter Tool. If pressure now holds at or above 30 psi, a fuel injector or the fuel rail is leaking.
12. Testing for check valve or fuel tube/line leakage: Clamp off the rubber hose portion of Adaptor Tool between the vehicle fuel line and test port on
Adapter Tool. If pressure now holds at or above 30 psi, a leak may be found at a fuel tube/line. If no leaks are found at fuel tubes or lines, the
check valve in the electric fuel pump is leaking. The fuel pump is not serviced separately. Replace the fuel pump module assembly.
