Fuel Pump: Testing and Inspection
FUEL PRESSURE TEST1. Check that battery voltage is at least 12 volts.
2. Disconnect battery negative terminal and the wiring connector from the cold start injector.
Disconnecting The Cold Start Injector Delivery Pipe:
3. Remove fuel delivery pipe between Cold Start Injector and fuel rail.
Use caution if the fuel system is still under pressure.
Connecting The Fuel Pressure Gauge:
4. Connect a suitable fuel pressure gauge to the fuel rail using the union bolt and gaskets to provide a tight seal.
5. Wipe off any gasoline that may have escaped when the fuel pipe was disconnected and reconnect negative battery terminal.
Installing A Service Wire On The Engine Check Connector:
6. Install a jumper wire between +B and FP of the check connector, turn on the ignition WITHOUT starting the engine and observe the fuel pressure gauge.
Fuel Pressure: 37 - 46 PSI (255 - 314 kPa)
7. If pressure is low, check fuel pump output and/or fuel filter for restrictions.
If pressure is high, continue checking FPR.
8. Remove the jumper wire from the check connector and start the engine.
Disconnect And Plug Vacuum Hose To FPR:
9. Disconnect vacuum sensor hose to Fuel Pressure Regulator, plug off the end, and observe gauge readings at idle.
Fuel Pressure: 37 - 46 PSI (255 - 314 kPa)
10. Reconnect the vacuum hose to the FPR and measure the fuel pressure at idling.
Fuel Pressure: 33 - 37 PSI (226 - 265 kPa)
11. If fuel pressure is not as specified, check the vacuum hose.
If no problems are found with the vacuum hose, replace the FPR. Refer to Fuel Pressure Regulator.
12. Stop the engine. Check that the fuel pressure remains above 21 psi (147 kPa) for 5 minutes after engine shutdown.
13. If not within specification, check the fuel pump and/or injectors.
If no problem is found, replace the Fuel Pressure Regulator.
14. Stop the engine and disconnect the fuel pressure gauge from the engine.
15. Using new gaskets, reinstall the fuel delivery pipe to the Cold Start Injector.
16. Wipe off any gasoline that may have escaped when the fuel pipe was disconnected.
17. Start the engine and check the Fuel Rail for cracks or signs of fuel leakage, especially around the fuel injectors.