Throttles of single-cylinder diesel engines are large and small.

The throttle of single-cylinder diesel engine is mainly related to the amount of oil sprayed from the nozzle, the atomization effect of gasoline and the mixing ratio with air. It is common that the injector is seriously dirty, blocking the injector, leading to poor injection, and lifting the throttle more or less every time. There are also the following reasons:

1. Large air volume: at idle speed, the air leakage in the cylinder is large and the energy loss in the cylinder is large, resulting in low compression temperature and pressure, poor fuel atomization and large combustion fluctuation.

2. Small oil supply: when idling, the oil supply is small, and the small change of oil supply of each cylinder will lead to different working conditions of each cylinder. This uneven fuel supply of each cylinder will lead to idling of diesel engine.

3. Unstable fuel supply: Direct injection of diesel engine makes the injection pressure develop to high pressure, especially the adoption of porous injector makes the nozzle inaccurate and easy to fluctuate when a small amount of fuel is supplied. Unstable fuel supply of diesel engine is an important reason for unstable idle speed.

4. System aging: With the increase of the service time of the fuel injection system, the fuel injection system is aging, and there are differences in components such as oil nozzles and oil delivery valves of each cylinder, which leads to further uneven oil quantity and aggravates idle fluctuation.