Sequence of work
1. Start the engine and let it run at idle speed.
2. With the engine running, use a stethoscope to check each injector for a clicking sound. This sound is the result of the injector nozzle valve opening and closing.
Attention! If you don't have a stethoscope, you can feel these clicks with a screwdriver or your fingers.
3. If you did not find characteristic sounds, and the engine is intermittent, then you should check the voltage supplied to the injectors, the resistance and tightness of the injectors.
Checking the supply voltage and resistance
4. To check the supply voltage, disconnect the injector connectors and install a diode test lamp between the contacts. Turn on the starter (helper needed), while the LED should flash.
5. If the light diode does not blink, then the malfunction may be in an open circuit and in the control unit.
6. To check the resistance of the injector, turn off the ignition and connect an ohmmeter to both injector contacts. If resistance is not correct, replace this injector.
Leak test
7. Remove the fuel injectors together with the fuel distributor without disconnecting the fuel lines.
8. Connect the connectors to the injectors.
9. Fix the nozzles in a suitable container.
10. Turn on the starter (helper needed). Compare jet injection nozzles. The jets must be cone shaped and uniform.
11. Turn off the ignition.
12. Disconnect the injector connectors.
13. Turn on the ignition for about 5 seconds without including the starter. Check the tightness of each nozzle: within 1 min. no more than 1 drop of fuel should flow out of the nozzle of each nozzle.
14. Install the injectors in the reverse order of removal.3. If you did not find characteristic sounds, and the engine is intermittent, then you should check the voltage supplied to the injectors, the resistance and tightness of the injectors.
Checking the supply voltage and resistance
1. To check the supply voltage, disconnect the injector connectors and install a diode test lamp between the contacts. Turn on the starter (helper needed), while the LED should flash.
2. If the light diode does not blink, then the malfunction may be in an open circuit and in the control unit.
3. To check the resistance of the injector, turn off the ignition and connect an ohmmeter to both injector contacts. If resistance is not correct, replace this injector.
Leak test
4. Remove the fuel injectors together with the fuel distributor without disconnecting the fuel lines.
5. Connect the connectors to the injectors.
6. Fix the nozzles in a suitable container.
7. Turn on the starter (helper needed). Compare jet injection nozzles. The jets must be cone shaped and uniform.
8. Turn off the ignition.
9. Disconnect the injector connectors.
10. Turn on the ignition for about 5 seconds without including the starter. Check the tightness of each nozzle: within 1 min. no more than 1 drop of fuel should flow out of the nozzle of each nozzle.
11. Install the injectors in the reverse order of removal.