Circuit Test

INJECTORS
The injectors inject fuel according to a signals from the ECM. The volume of fuel injected by the injector is determined by the time during which the solenoid valve is energized.

Circuit Diagram:

TROUBLESHOOTING HINTS
1. If the engine is difficult to start when it is hot, check low for fuel pressure and injector leaks.
2. If the injector does not operate when the engine is cranked, then check the following:
- Faulty power supply circuit to the ECM or faulty ground circuit.
- Faulty MFI control relay.
- Faulty crankshaft position sensor or camshaft position sensor.

3. If engine idle remains unchanged when fuel injection to the cylinders are is cut one after another, check for the following items about such cylinder:
- Injector and harness.
- Spark plug and high tension cable.
- Compression pressure.

4. If the injection system is OK but the injector drive time is out of specification, check for the following items:
- Poor combustion in the cylinder (faulty spark plug, ignition coil, compression pressure, etc.)

5. The MIL is on or the DTC is displayed on the HI-SCAN under the following condition.
- When the injector itself is faulty

Using Hi-Scan:

Harness Inspection Procedures:

INJECTOR INSPECTION

Operation Check




Using a HI-SCAN:
- Activate the fuel injectors in sequence.
- Check the operating time of the injectors.

Operation Sound Check
1. Using a stethoscope, check the injectors for a 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




1. Disconnect the connector at the injector and measure the resistance between the two terminals.
Standard value : 15.9 ± 0.35 ohm

2. Re-connect the connector to the injector.