Checking the fuel injection system (VW Passat B5)

In the fuel injection system, you can only check the main electrical circuits yourself.

If the engine is not running normally, first check the condition of the electrical wiring and connectors. Check the condition of the air filter element, as well as the condition and interelectrode gap of the spark plugs. Check the crankcase ventilation hoses for patency and the adjustment of the accelerator cable. If the engine still runs unsteadily, check the compression in the engine cylinders.

If you suspect a fuel injector is not working properly, clean it.

If the engine still runs rough, check the ignition system components.

If the fault is still present, check the integrity of the fuses and the condition of the electrical connectors and wiring. There should be no melted contacts, moisture, corrosion, dirt or other damage on the electrical connectors.

After performing an independent check, contact a specialized Volkswagen station for diagnostics of the fuel injection system using special equipment.