B4000 4WD V6-4.0L OHV (1995)
Fuel Pressure Regulator: Testing and Inspection
Warning: Before performing the following operation, release the fuel pressure from the fuel system to reduce the possibility of injury or fire.
INSPECTION
Fuel line pressure
1. Connect the SST.
2. Start the engine and run it at idle.
3. Measure the fuel line pressure.
Fuel line pressure: 240-280 kPa (35-40 psi)
4. Disconnect the vacuum hose from the pressure regulator and plug it.
5. Measure the fuel line pressure again.
Fuel line pressure: 240-310 kPa (35-45 psi)
6. If the fuel line pressure does not increase with the vacuum hose disconnected, or there is leakage from the pressure regulator, then replace the
pressure regulator.
7. Disconnect the vacuum hose from the pressure regulator and plug it.
8. Connect a vacuum pump to the pressure regulator.
9. Apply vacuum to the pressure regulator.
10. Verify the fuel line pressure decreases as vacuum increases.
11. If the fuel line pressure does not decrease when vacuum increases, replace the pressure regulator.
