Checking the EFI fuel injection system [Toyota 4Runner N120]

1. Check all ground connections for tightness. Check system wiring and connectors. Loose electrical connections and poor ground connections can be the cause of many faults that are observed as serious failures.

2. Check the battery charge level. The normal operation of the fuel metering sensors and actuators depends on the supply voltage.

3. Check the condition of the air filter.

4. If a blown fuse is found, replace it and check the operation of the corresponding circuit. If the fuse blows again, look for a shorted wire in the wiring.

5. Check the air duct for leaks.



6. Remove the air duct from the damper housing and check for resinous deposits and carbon deposits.



7. Place a stethoscope on the running engine (or a screwdriver) to each of the injectors and listen for characteristic clicks indicating normal operation of the injectors.





8. If necessary, a light indicator can be used.



9. Check the resistance of each injector.

10. Other checks should be performed at a car service center.