Mixture Control Unit
Airflow sensor housing contains sensor plate which moves in cone-shaped venturi. All engine intake air is drawn past sensor plate. Sensor plate, and attached hinged lever, moves with air drawn into engine.
Movement of sensor plate lever changes position of control plunger in fuel distributor. Control plunger is used to meter amount of fuel injected into each cylinder. Movement of plate is controlled by airflow, cone shape of venturi, counterbalance weight and fuel pressure.
NOTE:
Air flows UP through sensor housing on most inline engines, and DOWN through sensor housing on V6, V8 and turbocharged engines. Direction of airflow is changed for manufacturer's convenience in routing airflow.
Fuel distribution can be equal only if pressure to each injector is equal. Pressure regulating valves in fuel distributor equalize system pressure. These valves are adjusted during assembly of fuel distributor and cannot be adjusted in service.