Fuel Pressure: Testing and Inspection

Fuel System Schematic:

WARNING: To reduce the risk of fire and personal injury, it is necessary to relieve the fuel system pressure before connecting a fuel pressure test. A small amount of fuel may spill when disconnecting fuel hoses. Always wrap a shop towel around fittings to catch any fuel that may leak out. Refer to Fuel Pressure Release Procedure.


1. Loosen fuel filler cap to relieve fuel tank vapor pressure
2. Remove fuel pump fuse or disconnect electrical connector at fuel tank.
3. Start and run engine until fuel supply in fuel lines is exhausted and engine dies. Engage starter another 5 seconds to relieve any remaining pressure.
4. Disconnect negative battery cable to prevent fuel discharge if an accidental attempt is made to start the engine.
5. Disconnect fuel feed hose in engine compartment. Install J 29658B or BT-8205 gage and J 29658-85 or J 29658-89 adapter between the flexible hose and steel line. Tighten gage to insure leak-free connections.
6. Connect negative battery cable.
7. Reconnect fuel pump fuse or electrical connector at fuel pump.
8. Start car and observe fuel pressure reading. It should be 62 to 90 kPa (9 to 13 PSI). If not, refer to CHART A-7.
9. Disconnect negative battery cable and loosen filler cap to relieve tank vapor pressure.
10. Remove fuel pressure gage.
11. Install new O-rings as needed on fuel feed lines.
12. Reconnect fuel lines.
13. Connect negative battery cable.
14. Cycle ignition key ON to pressurize fuel system and check for leaks.
For fuel system and component pressure test, refer to Computers and Control Systems. Testing and Inspection