Porsche 1972 911 Workshop Manual page 161

M i x t u r e C o n t r o l U n i t
Air Flow Sensor and Fuel Distributor.
The air flow sensor consists of a venturi and a
sensor plate which is attached to a lever.
The volume of intake air passing through the
venturi determines. the position of the sensor
plate.
The control plunger and the slotted metering
cylinder are located in the center of the fuel
distributor. Machined into the metering cylinder
are 6 rectangular slots which act as metering
ports. They can b e progressively opened'by
the control plunger.
The metering ports open depending on the
position of the sensor plate whose moyement is
transmitted t o the control plunger through a lever
Intake air which passes through the air flow
sensor exerts a pneumatic force F l on the sensor
plate.
The pneumatic force is countered in the fuel
distributor by hydraulic force F2 which is exerted
against the control plunger through a port.
The sensor plate will yield until the pneumatic
force and hydraulic force equalize.
D e s c r i p t i o n
Venturi
1
2 Sensor plate
Lever
3
4 Control plunger
5 Slotted metering cylinder
6 Metering port
Fuel distributor