Fuel Pressure-Up System Test
- Ensure coolant temperature sensor and air temperature sensor (in airflow meter) and circuits are operating correctly. See SENSORS & SWITCHES .
- Fuel pressure-up system is controlled by ECU through a vacuum switching valve. The vacuum switching valve is fed current through the EFI main relay when the ignition is turned on. ECU controls the ground circuit. ECU will activate vacuum switching valve for 90-180 seconds when restarting engine at normal operating temperature. To check operation, See Fig 1 or Fig 2 .
FUEL PRESSURE-UP VACUUM SWITCHING VALVE LOCATION
| Model | Location |
|---|---|
| Pickup/4Runner (22R-E) | On Top Of Valve Cover |
| Pickup/4Runner (3VZ-E) | Right Front Fender (Center Vacuum Switching Valve) |