Fuel Injectors

INJECTORS

Description
The injectors inject fuel according to a signal coming from the engine control module. 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 hard to start when hot, check for fuel pressure and injector leaks.
2. If the injector does not operate when the engine is cranked, then check the followings;
- Faulty power supply circuit to the engine control module, faulty ground circuit.
- Faulty control relay.
- Faulty crankshaft position sensor, camshaft position sensor.
3. If there is any cylinder whose idle state remains unchanged when the fuel injection of injectors is cut one after another during idling, check for the following items about such cylinder.
- Injector and harness.
- Ignition 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 ignition plug, ignition coil, compression pressure, etc.)
- Loose EGR valve seating











Using scan Tool

Footnotes:
*1: The injector drive time refers to when the supply voltage is 11 volts and the cranking speed is less than 250 rpm.
*2: When engine coolant temperature is lower than 0° C (32° F), the engine control module fires all four cylinders simultaneously.
*3: When the vehicle is new (within initial operation of about 300 miles), the injector drive time may be about 10% longer.









Harness Inspection Procedure

Component Inspection

Operation Check
- Using a scan tool, check as described.
- Cut off the fuel injectors in sequence.
- Check the operation 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 engine control module.

Resistance Measurement Between Terminals
1. Disconnect the connector at the injector.





2. Measure the resistance between terminals.

Standard value: 13 - 16 ohms at 20° C (68° F)

3. Connect the connector to the injector.