DECELERATION FUEL CUT-OFF:
Describes a device that stops the flow of fuel to the carburettor or injectors when the vehicle rapidly decelerates in the event of an accident, preventing the possibility of a fire or explosion.
DIAPHRAGM: Describes a flexible cloth-rubber sheet stretched across an area, thereby separating two different compartments, is used in pumps to create a pressure differential liable to cause any fluid to be pushed or pulled from one point to another
DISCHARGE CHECK BALL: Describes a small check ball found in a carburettor that lifts off its position when the pump well is pressurised by the accelerator pump, allowing fuel to be discharged into the venturi through the shooter nozzle
DISCHARGE NOZZLE: Describes the end of the main delivery tube that discharges fuel into the venturi area of a carburettor.
DIVORCED CHOKE: Describes a vacuum diaphragm mounted on the carburettor where the choke lever is operated by a mechanical linkage rod from the bimetal spring. Sometimes described as a remote choke.
DOUBLE-BARREL CARBURETTOR: Describes the two throttle openings or barrels from the carburettor to the intake manifold.
DOWNDRAFT CARBURETTOR: Describes a carburettor in which the air passes down into the intake manifold.
DRY SETTING: Describes the act of adjusting the float with a graduated rule while the carburettor is disassembled on the bench.
ENRICHMENT UNIT: Describes a circuit in a carburettor set to provide a richer mixture-the unit is operated through engine vacuum
ENRICHNER: Describes a type of fuel plunger used in a carburettor in place of a choke. By activating the plunger, more gas is permitted into the intake area to enrichen the fuel-air mixture for easier starting.
FAST IDLE CAM: Describes a cam in a carburettor that opens the throttle slightly when the choke is brought into operation.
FAST IDLE SCREW: Describes a screw on a carburettor used to adjust the fast idle's speed.
FEEDBACK CARBURETTOR(FBC): Describes a carburettor regulated by a closed-loop system (computer, solenoid-controlled valve, catalytic converter, oxygen sensor, among others,) providing and adjusting the air-fuel mixture quality to operate a catalytic converter
FEEDBACK CARBURETTOR ACTUATOR: Describes a computer-controlled stepper motor that varies the carburettor air/fuel mixture.
FEEDBACK CONTROL: Describes a closed-loop control.
FEED PIPE: Describes a pipe that supplies liquid or gas.
FIXED-CHOKE CARBURETTOR: Describes s carburettor where the choke tube or venturi is of predetermined size.
FIXED-JET CARBURETTOR: Describes the most common type of carburettor in which the jets and choke are of a predetermined size.
FLOAT LEVEL: Defines the height of the fuel in the carburettor float bowl.
FLOAT NEEDLE: Describes a needle in the carburettor activated by fuel level in the float bowl.
FOUR-BARREL CARBURETTOR: 
Describes a carburettor, usually found on large V-8 engines, with four barrels that operates like dual carburettors, with the second carburettor (third and fourth barrels) cutting in only at high speeds.
