11. Electric Fuel Pump Pressure Test

11. ELECTRIC FUEL PUMP PRESSURE TEST

NOTE: The fuel pump runs for approximately 30 seconds at initial ignition on and then the pressure decreases.

Purpose:
The purpose of this test is to verify there is sufficient fuel pressure for starting.

Electric Fuel Pump Pressure Test
- Verify there is fuel in the tank.
- Check the fuel pump power and ground circuits.
- Measure the fuel pressure using the Fuel Line Adapter 310-159 or equivalent.

NOTE: If using a scan tool for the fuel pump pressure test, the scan tool value may vary by 10% on the 20.7 kPa (3 psi) specification.







Recommended Procedure:
Verify there is fuel in the tank and battery voltage at the fuel pump. With the ignition ON and engine OFF use a digital multimeter (DMM), and measure the voltage between the fuel pump power and ground circuits. Battery voltage is present for approximately 30 seconds after the ignition is turned to the ON position. If no voltage is present, GO to Pinpoint Test MA to continue diagnosis. Test MA: Fuel Pump Control - Low Pressure Pump







Disconnect the fuel line on the outlet side of the fuel conditioning module. Install the Fuel Line Adapter 310-159 or equivalent and the Magnehelic Gauge(R) 0-200 kPa (0-30 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent). Measure the fuel pressure with the ignition in the ON position and the engine OFF. If fuel pressure is below 20.7 kPa (3 psi), go to the next step to verify no restriction.

If the engine stalls while driving, carry out the Electric Fuel Pump Pressure Test in the Performance Diagnostic Procedures to continue diagnosis. 13. Electric Fuel Pump Pressure







Possible Causes:
- Dirty or restricted fuel filters
- Fuel pump relay
- Inertia switch
- Leak in the low pressure supply line

Tools Required:
Magnehelic Gauge(R) 0-200 kPa (0-30 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)

Fuel Line Adapter 310-159 or equivalent