Fuel Pump Pressure Test
FUEL SYSTEM PRESSURE TEST1. Remove air induction tube.
WARNING: Whenever fuel line fittings are loosened or removed, wrap a shop cloth around fitting while connecting gauge, to collect fuel place the cloth in an approved container.
Fuel System Pressure Relief:
2. Connect fuel gage bar kit (Saturn Tool) SA9127E to fuel pressure test port Use 90° adapter SA9403E.
3. Install bleed hose into an approved container and open valve to bleed off any fuel in the system.
4. Close the fuel pressure gauge shut-off valve.
IMPORTANT: Battery must be at a minimum of 12 volts when performing a fuel system pressure test.
a. Turn ignition key to ON position (do not start engine_ and record maximum pressure. Cycle the key on and off several times to establish an accurate reading. Allow gage pressure to stabilize for thirty seconds. Refer to readings below.
- Minimum System Pressure: 262 kPa (38 psi)
- Minimum System Leakdown (in five minutes):
^ New Vehicle: 20 kPa (3 psi)
^ Service Limit: 41 kPa (6 psi)
IMPORTANT: The fuel pressure should be bled off and the test repeated a minimum of two times.
5. If pressure bleeds off beyond specifications, install fuel rail return plug SA9410E, available in gauge bar kit.
6. Turn ignition key to the on position (do not start engine) and record maximum pressure. Cycle the key on and off several times to establish an accurate reading. Allow gage pressure to stabilize for thirty seconds. Refer to readings below.
- Minimum System Pressure (fuel rail plugged): 317 kPa (46 psi)
- Maximum Leakdown (in five minutes):
^ New Vehicle: 41 kPa (6 psi)
^ Service Limit: 55 kPa (8 psi)
NOTE: The fuel pressure should be bled off and the test repeated a minimum of two times.
7. If pressure bleeds does not leak off beyond specifications, replace the fuel rail pressure regulator
8. If pressure does bleed off beyond specifications:
a. Check for fuel leaks at suction line.
b. Perform fuel injector tip/leakage test.
c. Perform fuel pump pressure test.
NOTE: If the fuel pressure only bleeds off with the fuel rail return plugged, perform a fuel pump pressure test and check for leakage. If the fuel pump pressure does not bleed off, perform an injector leakage pressure test. SFI engines require the fuel rail to be removed for the fuel injector leak down test.
9. Install bleed hose into an approved container and open shut-off valve to bleed system pressure. Once pressure is bled, remove gage bar adapter from fuel pressure test port and install cap.
NOTE: If a start/stall condition exists after the vehicle has sat for ten hours or less, and fuel pressure readings are extremely low during previous testing, a four hour fuel system pressure test should be performed.