What is the reason for the serious engine jitter of large trucks?

There are many reasons why the truck engine vibrates violently, as follows: 1, the engine has a serious carbon deposit, and the most common reason for automobile vibration is that the throttle valve is too dirty or the nozzle has too much carbon deposit. When there is too much carbon deposit in the engine, the gasoline sprayed by the fuel nozzle will be absorbed by the carbon deposit during cold start; 2. The mixture causing cold start is too thin, making it difficult to start. In this case, only when the gasoline absorbed by carbon deposits is saturated can it easily enter the car. After entering the car, the gasoline adsorbed on the carbon deposit will be sucked into the cylinder by the vacuum suction of the engine and burned, making the mixture rich. 3. The engine combustible mixture is sometimes rare and sometimes rich, which leads to idle jitter after cold start. The lower the temperature, the more engine oil and carbon deposit are needed for cold start, which will affect the smooth progress of cold start.