Fuel metering device means the carburetor, or in the case of certain engines the fuel injector, fuel distributor or fuel injection pump.
Throttle means the component of the fuel metering device that connects to the driver-operated accelerator control system and that by input from the driver-operated accelerator control system controls the engine speed.
Idle position means the position of the throttle at which it first comes in contact with an engine idle speed control appropriate for existing conditions according to the manufacturers' recommendations. These conditions include, but are not limited to, engine speed adjustments for cold engine, air conditioning, and emission control, and the use of throttle setting devices.
Ambient temperature means the surrounding air temperature, at a distance such that it is not significantly affected by heat from the vehicle under test.
49 C.F.R. §571.124