Fuel Injector Inspection
FUEL INJECTOR INSPECTIONStep 1 - 3:
Fuel Injector Operation Inspection
WARNING: To prevent serious injury or damage, always perform diagnosis while referring to the warnings and cautions in each procedure when inspecting or repairing the fuel system.
Fuel Cut Control Inspection
1. Connect the WDS or equivalent to the DLC-2.
2. Warm up the engine and idle it.
3. Turn off all the electrical loads and the A/C switch.
4. Using "RPM" of the PID/data monitor function, verify the engine speed.
5. Using a soundscope or screwdriver, verify the operation sound of the fuel injector at all cylinders.
1. Open the throttle valve and increase the engine speed to 4,000 rpm.
2. Close the throttle valve instantaneously and verify that the fuel injector operation sound stops until the engine speed decreases to approx. 2,200 rpm and the sound is heard when the engine speed is approx. 2,200 rpm or less.
- If the sound does not stop at all cylinders, inspect the following:
- PCM input signal circuit (sensor, wiring harness)
- Throttle opening signal (throttle position sensor)
- If the sound does not stop at specific cylinders, inspect the following:
- Corresponding fuel injector and related wiring harnesses and connectors
- If the operation sound stops at all cylinders but the engine speed at which the operation sound recovers is not within the specification, inspect the following:
- PCM input signal circuit (sensor, wiring harness)
- Load/no load detection signal (neutral/clutch switch (MTX), transaxle range switch (ATX))
- Water temperature signal (water temperature sensor)
6. Place the vehicle on a chassis dynamometer.
7. Inspect the following using the WDS or equivalent.
1. Verify the injector actuation time using the PID/data monitor function.
2. Depress the accelerator pedal and increase the engine speed to 4,000 rpm. (Loaded range)
3. With the accelerator pedal released (without depressing the brake pedal), verify that the injector actuation time of 0 ms is indicated until the engine speed decreases to approx. 2,200 rpm, and then the actuation time 2 - 5 ms is indicated when the engine speed decreases to approx. 870 rpm or less (MTX) or 820 or less(ATX).
- If it cannot be verified, inspect the PCM input signal circuit.
- Load/no load detection signal (neutral/clutch switch (MTX), transaxle range switch (ATX))
Resistance Inspection
1. Turn the ignition switch to the LOCK position.
2. Disconnect the negative battery cable.
3. Disconnect the fuel injector connector.
4. Inspect the resistance between fuel injector terminals A and B using a tester.
- If within the specification, perform the "Circuit Open/Short Inspection".
- If not within the specification, replace the fuel injector.
Fuel injector resistance
California emission regulation applicable model: 13.1 - 14.5 Ohms [20 °C {68 °F}]
Except for California emission regulation applicable model: 11.4 - 12.6 Ohms [20 °C{68 °F}]
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Inspect the following wiring harnesses for open or short circuit (continuity check).
Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- Fuel injector No.1 terminal A and PCM terminal 2BB
- Fuel injector No.2 terminal A and PCM terminal 2BC
- Fuel injector No.3 terminal A and PCM terminal 2BD
- Fuel injector No.4 terminal A and PCM terminal 2AZ
- Fuel injector No.1 terminal B and main relay terminal B
- Fuel injector No.2 terminal B and main relay terminal B
- Fuel injector No.3 terminal B and main relay terminal B
- Fuel injector No.4 terminal B and main relay terminal B
Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- Fuel injector No.1 terminal A and body GND
- Fuel injector No.2 terminal A and body GND
- Fuel injector No.3 terminal A and body GND
- Fuel injector No.4 terminal A and body GND
Leakage Inspection
WARNING: Fuel line spills and leakage from the pressurized fuel system are dangerous. Fuel can ignite and cause serious injury or death and damage. To prevent this, complete the following inspection with the engine stopped.
1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel from spilling from the fuel system.
2. Disconnect the negative battery cable.
3. Remove the fuel injector and fuel distributor as a single unit.
4. Fix the fuel injector to the fuel distributor with a wire or the equivalent.
5. Connect the fuel hose.
6. Start the fuel pump using the following procedure:
Using WDS or equivalent
1. Connect the WDS or equivalent to the DLC-2.
2. Start the fuel pump using the "FP" simulation function.
Not using WDS or equivalent
1. Remove the fuel pump relay.
CAUTION: Be careful to short the specified terminal as shorting the wrong terminal of the main fuse block may cause a malfunction.
2. Using a jumper wire, short fuel pump relay terminals C and D and connect the negative battery cable to start the fuel pump.
7. Tilt the fuel injector at an angle of 60 ° to inspect for leakage.
- If not within the specification, replace the fuel injector.
Standard
Less than 1 drop/2 min
8. Stop the fuel pump using the following procedure:
Using WDS or equivalent
1. Stop the fuel pump using the "FP" simulation function.
Not using WDS or equivalent
1. Disconnect the negative battery cable to stop the fuel pump.
9. Disconnect the negative battery cable, (using WDS or equivalent)
10. Remove the wire or equivalent securing the fuel injector.
11. Install the fuel injector.
12. Inspect all related parts by performing "AFTER SERVICE PRECAUTION".
Injection Volume Inspection
WARNING: Fuel line spills and leakage from the pressurized fuel system are dangerous. Fuel can ignite and cause serious injury or death and damage. To prevent this, complete the following inspection with the engine stopped.
1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel from spilling from the fuel system.
2. Disconnect the negative battery cable.
3. Remove the fuel injector.
4. Connect the fuel injector to the fuel injector tester.
5. Start the fuel pump using the following procedure:
Using WDS or equivalent
1. Connect the WDS or equivalent to the DLC-2.
2. Start the fuel pump using the "FP" simulation function.
Not using WDS or equivalent
1. Remove the fuel pump relay.
CAUTION: Be careful to short the specified terminal as shorting the wrong terminal of the main fuse block may cause a malfunction.
2. Using a jumper wire, short fuel pump relay terminals C and D and connect the negative battery cable to start the fuel pump.
6. Measure the injection volume of each fuel injector.
- If not within the specification, replace the fuel injector.
Standard
For California emission regulation applicable model: 260 - 320 ml {260 - 320 cc, 15.9 - 19.5 cu in}/min
Except for California emission regulation applicable model, LF-DE: 195 - 245 ml {195 - 245 cc. 11.9 - 14.9 cu in}/min
Except for California emission regulation applicable model, L3-VE: 230 - 290 ml {230 - 290 cc, 14.1 - 17.6 cu in}/min
7. Disconnect the negative battery cable.
8. Install the fuel injector.
9. Inspect all related parts by performing "AFTER SERVICE PRECAUTION".
Atomization Inspection
1. Inspect the atomization status.
- If not normal, replace the fuel injector.