B4000 4WD V6-4.0L OHV (1995)
High pressure inspection
1. Connect the SST.
2. Disconnect the fuel return line from the fuel rail.
3. Connect a short hose from the fuel rail to a one liter (one quart) measuring container.
4. Connect SST NGS to the data link connector and select active command mode.
5. Select fuel pump relay control. Turn relay on for 10 seconds.
6. Measure the fuel line pressure and verify fuel is flowing into container.
7. If the fuel line pressure is still high, then replace the pressure regulator.
8. If the fuel line pressure is OK, then inspect the fuel return line for a clog.
9. Remove SST (NGS).
Diaphragm inspection
1. Start the engine and run it at idle for 10 seconds.
2. Turn the ignition switch OFF for 10 seconds.
3. Start the engine and run it at idle for 10 seconds.
4. Turn the ignition switch OFF.
5. Disconnect the vacuum hose from the pressure regulator.
6. Check the vacuum port on the pressure regulator.
7. If the diaphragm is leaking fuel, replace the pressure regulator.