Checking the air flow meter pressure disc (BMW 3 Series E21)

Make sure that in the initial position the upper edge of the air flow meter pressure disc is level with the base of the air flow meter body cone or no more than 5 mm below it.

If necessary, adjust the position of the air flow meter pressure disk by bending the spring clip.

Check the installation of the pressure disc by placing a 0.10 mm thick gasket at four points around the circumference.

If the pressure disk is not in the correct position, loosen the adjusting screw 3, center the pressure disk, and then tighten screw 3 to a torque of 0.5 kgf·m.