Carburetor: Description and Operation

Fig. 3 Motorcraft model 2150A 2 barrel feedback carburetor exploded view. 1983 - 86:

Motorcraft model 2150A 2 barrel feedback carburetor

Fig. 4 Motorcraft model 2150 2 barrel non-feedback carburetor exploded view. 1984 - 85:

Motorcraft model 2150 2 barrel non-feedback carburetor

Fig. 1 Motorcraft model 2150 2 barrel carburetor less altitude compensator, exploded view:

The Motorcraft 2150 carburetor has two main bodies, the air horn and the throttle body. The air horn assembly, which serves as a cover for the throttle body, contains the choke plate and vents for the fuel bowl. On 2150 units installed on V-6 engines, the air horn assembly contains a fuel deceleration system which consists of a metered pickup orifice in the fuel bowl and air/fuel mixing orifices and bleeds.
An electric choke system is incorporated which opens choke plate within 1 - 1-1/2 minutes when under hood temperatures are above approximately 55° to 60°. The electric choke system is supplied current to open the choke when under hood temperatures are between 54 and 74° F.
Some 2150 units are equipped with an altitude compensation aneroid to improve high altitude emission control and driveability. Intake air entering the bypass valve is metered into the air flow above the throttle plates, leaning the mixture for high altitude operation. Air flow is controlled by a valve activated by an aneroid attached to the rear of the carburetor main body. Also, these units are equipped with a choke in the bypass air intake, linked to the main choke.
The throttle plate, accelerating pump, power (enrichment) valve and fuel bowl are in the throttle body. The choke housing is attached to the throttle body.
The two bodies each contain a main and booster venturi, main fuel discharge, accelerating pump discharge, idle fuel discharge, and a throttle plate. On some units, an anti-stall dashpot is attached to the carburetor when the vehicle is equipped with an automatic transmission.
Some vehicles use a feedback carburetor. The air horn assembly used on the feedback carburetor has an auxiliary fresh air intake for the duty cycle solenoid/altitude compensator.
The main body used on feedback carburetors has a provision at the back to attach the duty cycle solenoid/altitude compensator as well as an opening that accepts auxiliary fresh air from the horn and channels that link up to the bleed circuits to the booster support assembly. There is also a throttle angle potentiometer mounted on the throttle at the choke side.
The booster support assembly has cast in channels that flow bleed air to the idle and main system vacuum circuit.