What are the acceleration conditions of automobile engines?

Acceleration condition: the throttle valve suddenly opens, which makes the engine speed rise rapidly. This is the acceleration condition. When the throttle valve is suddenly opened, the speed and flow of air flowing through the carburetor and the vacuum degree of the throat increase rapidly. However, because the inertia of liquid fuel is much greater than that of air, the increase of its flow rate is much slower than that of air, resulting in the temporary dilution of mixed gas.

On the other hand, when the throttle valve is suddenly opened, a large amount of air enters the intake pipe, resulting in a sudden increase in the pressure in the intake pipe. At the same time, because the cold air cannot be preheated, the temperature in the intake pipe decreases, which is not conducive to the evaporation of gasoline in the mixture, resulting in a relative decrease in the evaporation of fuel. So unless extra fuel is added, the mixture is too thin, which not only can't accelerate the engine, but also can cause the engine to stall? .

In order to improve the acceleration performance of the engine, it is required that the carburetor can supply a certain amount of extra gasoline at one time when the throttle valve is suddenly opened, so as to enrich the mixture.