The maintenance technicians tested the 0R-3002 injectors and found that the fuel atomization effect was poor, and the fuel was not fully atomized, leading to insufficient combustion and carbon deposition in the cylinder. The reason for the poor atomization was that the nozzle holes were blocked by carbon deposits and the pressure regulating spring was aging, leading to the decrease of injection pressure. In addition, the generator set had been working in a high-load environment for a long time, which also accelerated the carbon deposition.