Contents: Checking the supply voltage and…↡ Checking for leaks ↡ Checking the supply voltage and…↡ Checking for leaks ↡
Sequence of works
1. Start the engine and let it run at idle speed.
2. With the engine running, check each injector with a stethoscope to see if there is a clicking sound. This sound is caused by 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 have not detected any characteristic sounds, and the engine runs intermittently, then you should check the supply 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 (assistant needed), while the LED should blink.
5. If the LED does not blink, the fault may be in the electrical circuit break and in the control unit.
6. To check the injector resistance, turn off the ignition and connect an ohmmeter to both injector terminals. If the resistance does not match the required value, replace this injector.
Checking for leaks
7. Remove the fuel injectors together with the fuel distributor without disconnecting the fuel lines.
8. Connect the contact connectors to the injectors.
9. Secure the nozzles in a suitable container.
10. Turn on the starter (assistant needed). Compare the injection jets of the injectors. The jets should be cone-shaped and identical.
11. Turn off the ignition.
12. Disconnect the injector connectors.
13. Turn on the ignition for about 5 seconds without turning on the starter. Check the tightness of each injector: no more than 1 drop of fuel should flow out of the nozzle of each injector within 1 minute.
14. Install the injectors in the reverse order of removal.3. If you do not detect any characteristic sounds, and the engine runs intermittently, then you should check the supply 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 (assistant needed), while the LED should blink.
2. If the LED does not blink, the fault may be in the electrical circuit break and in the control unit.
[Publication taken from an online resource: MercedesMan.ru]
3. To check the resistance of the injector, turn off the ignition and connect an ohmmeter to both contacts of the injector. If the resistance does not correspond to the required value, replace this injector.
Checking for leaks
4. Remove the fuel injectors together with the fuel distributor without disconnecting the fuel lines.
5. Connect the contact connectors to the injectors.
6. Secure the nozzles in a suitable container.
7. Turn on the starter (assistant needed). Compare the injection jets of the injectors. The jets should be cone-shaped and identical.
8. Turn off the ignition.
9. Disconnect the injector connectors.
10. Turn on the ignition for about 5 seconds without turning on the starter. Check the tightness of each injector: no more than 1 drop of fuel should flow out of the nozzle of each injector within 1 minute.
11. Install the injectors in the reverse order of removal.