Note. Before starting work, read the precautions in Section Safety precautions and cleanliness when working with the fuel system.
If a malfunction of the fuel injection system is detected, first of all, make sure that all connectors are connected securely and that there are no signs of corrosion on their surfaces. Next, make sure that the malfunction is not caused by neglect of regular maintenance (check air cleaner, valve clearances, cylinder compression, fuel filter). Also check that the crankcase ventilation hoses are not blocked (see chapter Current service).
If, after carrying out the checks described above, the cause of the malfunction is not found, drive the car to a service station for diagnostics. At the bottom of the dashboard on the driver's side there is a diagnostic socket, to which special diagnostic equipment is connected. This equipment reads fault codes stored in the memory of the control unit.
Fault codes can be read using a special diagnostic scanner available at the service station, or a personal computer with a special board, program and cable.
By reading the codes, you can easily detect a malfunction, even if it is not obvious. You can check any component without using a diagnostic code scanner, but keep in mind that non-professional intervention in the system can damage electronic components.
If you have a diesel tachometer or other suitable equipment, you can measure the idle speed. But these parameters are not adjusted. The reason for the deviation of the idle speed may be faulty injectors. In this case, they must be cleaned and calibrated. The service life of the injectors is unlimited, but it may happen that you have to repair or replace them after driving approximately 100,000 kilometers. Repair and calibration of injectors should be carried out by a specialist.