Fuel Injector: Testing and Inspection

CIRCUIT DIAGRAM











USING SCAN TOOL

















HARNESS INSPECTION PROCEDURES

USING OSCILLOSCOPE
1. Power supply side of injector
- Run the engine at idle speed.





- Connect the probe to the oscilloscope pick-up point 2 as shown in the circuit diagram, and check the waveform of each injector.

NOTE: Since the injector for the Non-Turbo system is a high-resistance type, the waveform becomes similar to that of the upstream of the resistor for the Turbo system.

2. Drive side of injector
- Run the engine at idle speed.





- Connect the probe to the oscilloscope pick-up point 3 as shown in the circuit diagram, and check the waveform at the drive side of each injector.

ACTUATOR INSPECTION
Checking Operation Sound





Using a sound scope, check the operation sound (ticking) of injectors during idling or during cranking.
Check that as the rotating speed increases, the frequency of the operating sound also increases.

Caution: Note that even if the injector you are checking is not operating, you will hear the operating sound of the other injectors.

NOTE: If no operating sound is heard from the injector that is being checked, check the injector drive circuit. If there is nothing wrong with the circuit, a defective injector or engine control module is suspected.

Measuring Resistance Between Terminals
1. Remove the injector connector.





2. Measure the resistance between terminals.

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

3. Install the injector connector.