Fuel Injector: Testing and Inspection

CIRCUIT DIAGRAM




INSPECTION
1. Measure the resistance of the injectors between the terminals using an ohmmeter.

Resistance 13-16 W [at 20 °C (68 °F)]

2. If the resistance is not within specifications, replace the injector.

INJECTOR CHECKING







USING HI-SCAN

NOTE:
1. The injector drive time is when the supply voltage is 11 V and the cranking speed is less than 250 rpm.
2. When engine coolant temperature is lower than 0 °C (32 °F), the ECM fires all four cylinders simultaneously.




3. When the vehicle is new (within initial operation of about 500 km [300 miles]), the injector drive time may be about 10% longer.

Using stethoscope and voltmeter

Operation Sound Check




1. Using a stethoscope, check the injectors for clicking sound at idle. Check that the sound is produced at shorter intervals as the engine speed increases.

NOTE: Ensure that the sound from an adjacent injector is not being transmitted along the delivery pipe to an inoperative injector.




2. If a stethoscope is not available, check the injector operation with your finger. If no vibrations are felt, check the wiring connector, injector, or injection signal from ECM.




Resistance Measurement Between Terminals
3. Disconnect the connector at the injector.
4. Measure the resistance between terminals.

Standard value 13-16 W [at 20 °C (68 °F)]

5. Connector the connector to the injector.







HARNESS INSPECTION