What phenomenon occurs when fuel vaporizes due to excessive heat?

The phenomenon that occurs when fuel vaporizes due to excessive heat is known as vapor lock. This situation is particularly relevant in fuel systems, such as those in cars, where liquid fuel can become vaporized if the temperature rises significantly. When this happens, the vaporized fuel can lead to a situation where the fuel can't be effectively pumped to the engine, causing engine performance issues or even failure to start.

In high-temperature conditions, especially when the fuel lines or fuel tank are exposed to heat sources, the liquid fuel can reach its boiling point, creating vapor instead of allowing for a continuous flow of liquid fuel. This is especially problematic in gasoline engines, where maintaining a consistent flow of liquid fuel is crucial for proper operation.

The other options refer to different concepts: fuel mist refers to improperly atomized fuel that may be present in certain combustion systems, fuel evaporation is a general term that describes the transition of liquid fuel to a gas, and heat soak refers to the retention of heat in components after the heat source is removed, which does not specifically address the vaporization of fuel due to excessive heat.