Engine Coolant Temperature sensor.

Hi, I didn´t understand well how the fuel gets condensed, when the engine is at 80 degrees the fuel tends to evaporate creating an easy combustible vapor form but how the engine needs less fuel if it is getting evaporated? And when cold the fuel gets condensed, making it hard to ignite, that´s why the engine needs more fuel, but why is that? How the combustion process reacts to evaporation and condensation of the fuel. Any help is appreciated.

Hi Luis,

When the fuel is in a liquid state, it is not readily combustible even when exposed to a source of heat (in this case a spark plug and the higher temperatures caused by the compression stroke) so it needs to go through a phase change into a gaseous state for combustion to occur. As this is not an instantaneous change, more or less fuel is required to be added into the mixture to compensate.

Have a look at BLEVE incidents to see the difference between a fuel burning in a liquid state and a vapour.

Thank u so much