What component will be used to aid in a cold engine start?

What component will be used to aid in a cold engine start?

• A. Choke
• B. Spark plug
• C. Glow plug
• D. Throttle

Answer: (A)

A choke is used to aid in starting a cold engine by enriching the fuel mixture. When the engine is cold, fuel vaporizes poorly, so closing the choke reduces the air supply and increases the fuel fraction, making ignition easier. Once the engine warms up, the choke is opened to restore the normal air–fuel ratio. Spark plugs provide ignition, glow plugs heat diesel cylinders for cold starts, and throttling mainly controls air flow for speed rather than starting.

A choke is used to aid in starting a cold engine by enriching the fuel mixture. When the engine is cold, fuel vaporizes poorly, so closing the choke reduces the air supply and increases the fuel fraction, making ignition easier. Once the engine warms up, the choke is opened to restore the normal air–fuel ratio. Spark plugs provide ignition, glow plugs heat diesel cylinders for cold starts, and throttling mainly controls air flow for speed rather than starting.