1990-93 VW Passat
The fuel distributor is mounted on the mechanical air mass sensor. As air flows into the air cleaner and up through the sensor assembly, the air pushes the sensor plate up, which lifts up the fuel distributor plunger. When the engine is not running, the arm that the plate is bolted to rests on a spring. This allows some opposite movement of the plate if the engine backfires. There is no service procedure that requires disassembly of the airflow sensor. If the plate is removed, a special tool is required to center the plate in the bore.
- Relieve the fuel system pressure. See "Relieving Fuel System Pressure."
- Clean and dry all fuel line fittings on the fuel distributor.
- Loosen fuel line fitting bolts on the fuel distributor.
- Remove the fuel lines from the fuel distributor, label lines to insure proper installation.
- Remove the 2 small mounting screws from the top of the fuel distributor.
- Pull the fuel distributor from the airflow sensor.
- Remove the sealing O-ring from the airflow sensor then clean the O-ring groove.
- Install a new fuel distributor O-ring into the airflow sensor groove.
- Install the fuel distributor on the airflow sensor, be certain the O-ring stays in the groove.
- Install the fuel distributor mounting screws. Torque them to 2.5 ft. lbs. (3.5 Nm).
- Reinstall the fuel lines to the fuel distributor using new sealing washers on either side of the fuel line fittings.
- Tighten the fuel lines to 7 ft. lbs. (10 Nm).
- Start the engine and check for any fuel leaks.