Fuel Pressure: Testing and Inspection
FUEL PUMP PRESSURE AND CHECK VALVE TESTFuel Supply Line Connection To Fuel Rail:
Connecting Pressure Gauge:
1. Connect fuel pressure gauge between fuel supply line and fuel rail using adapters, as shown in illustration.
2. Set valve on pressure gauge block to the closed position.
2. Operate fuel pump until gauge pressure is approx. 80 psi (5.5 bar), then turn pump "OFF", noting pressure. (Operate pump by bridging terminals of fuel pump relay socket as in step 2 of electrical test above.)
3. Wait 10 minutes and note pressure drop.
^ Pressure drop should not excede 7.4 psi (0.5 bar).
If pressure drop is greater than specified, check hoses and connections for leaks. If no leaks are found, replace fuel pump check valve.
FUEL PUMP VOLUME TEST
Checking Fuel Pump Volume:
1. Disconnect fuel hose from gauge and push a long piece of hose over the supply line from the pump, directing open end of extra hose into a suitable measuring container (see illustration).
2. Remove fuel filler cap.
3. Connect voltmeter between electrical terminals of fuel pump, with pump connected.
4. Energize fuel pump for 15 seconds (see step 2 of electrical test above) and note operating voltage at the pump.
Fuel Pump Volume Vs. Supply Voltage:
5. Check volume of fuel in container after 15 seconds of operation and compare with chart.
^ If volume is less than that specified for the noted operating voltage, check for restricted or plugged fuel filter and/or supply line. If filter and line are OK, replace fuel pump.