Definition

Noun: A device in a vehicle's carburetor that automatically regulates the amount of air entering the engine when it is cold, enriching the fuel-air mixture to aid starting.

Usage

The automatic choke is a component of older gasoline engines with carburetors. It functions without driver input, adjusting itself based on engine temperature to ensure reliable cold starts.

Examples

• The car wouldn't start in the winter until I had the automatic choke repaired.
• Older engines used an automatic choke, while modern fuel-injected systems do not require one.
• A malfunctioning automatic choke can cause the engine to run poorly or stall.

Advanced Usage

• Technical Context: In automotive engineering, the automatic choke typically uses a bimetallic spring or a wax pellet that expands and contracts with heat, mechanically opening or closing the choke valve.

Variants and Related Words

• Choke (noun): The general device for restricting airflow to enrich the fuel mixture. A manual choke requires the driver to operate a lever or knob.
• Carburetor (noun): The device in which the choke is located, responsible for mixing air and fuel for an internal combustion engine.

Synonyms

• Self-regulating choke
• Auto choke

Notes

The term automatic choke is specific to carbureted engines. It is largely historical in everyday language, as most modern vehicles use electronic fuel injection which manages the air-fuel mixture digitally without a mechanical choke.

Noun

1. a choke that automatically controls the flow of air to the carburetor