9. High Pressure Fuel System Test
9. HIGH PRESSURE FUEL SYSTEM TESTNOTE: Carry out the Electric Fuel Pump Pressure test before carrying out the High Pressure Fuel System test. 13. Electric Fuel Pump Pressure
Purpose:
The purpose of this test is to determine if the high pressure fuel system is able to reach and maintain the requested desired fuel pressure for a calibrated amount of time. This procedure may be used to assist in diagnosing hard start/no start or driveability concerns.
High Pressure Fuel System Test
NOTE: Depending on the engine state the fuel rail pressure may vary at idle from 34.47 MPa (5,000 PSI) to 51.71 MPa (7,500 PSI).
- Use the scan tool to carry out the High Pressure Fuel System test.
- Visually check for engine compartment fuel leaks during this test.
Recommended Procedure:
NOTE: Follow the scan tool directions when carrying out the high pressure fuel system test.
This test determines if the high pressure fuel system is able to maintain the requested fuel pressure for a calibrated amount of time.
- Turn off all accessories. If the vehicle is equipped with a PTO system or auxiliary idle control, it must be turned off to carry out the high pressure fuel system test. Refer to the scan tool operating manual for instructions.
- Key in OFF position.
- Carry out the high pressure fuel system test.
- Visually check for engine compartment fuel leaks during this test.
- If visible fuel leaks are present, refer to Fuel Delivery and Air Induction, Fuel Charging And Controls.
- If the measured variation is outside of the specifications and no visible fuel leaks are present. GO to Pinpoint Test ME. Tests ME: Fuel Pump Control - High Pressure Fuel Injection Pump
Possible Causes:
- High pressure fuel injection pump
- Fuel pressure control valve
- Fuel volume control valve
- High pressure fuel system leak
- Fuel injectors
Tools Required:
Scan tool