Air Flow Meter/Sensor: Description and Operation

Fig. 2 Typical Bosch Air Flow Sensor:

The air flow sensor, Fig. 2, continuously measures air flowing into the engine and transmits this information to the fuel distributor. The air flow sensor consists of an air venturi (1) and an air flow sensor plate (2) which moves in the venturi. The plate is attached to a lever (3) which transmits the movement of the plate through a flange (4) to the control plunger in the fuel distributor. The weight of the sensor plate and lever is counterbalanced by a counterweight (5). The adjustment screw (7) is attached to a lever (6) and is used to adjust CO level.