To increase the reliability of the Diesel Engine from the occurrence of interference with the Fuel Injection Valve, it is necessary to calibrate the Fuel Injection Valve. Disturbances that occur with an indication of the absence of atomizing and the condition of the Fuel Injection Valve that is cracked. The results of the Fractography test indicated that there was Fatique Stress on the Fuel Injection Valve material. The sample injector has failed due to Fatigue Stress with originating cracks on its surface. The initial crack is defined as the origin of the crack, then surrounded by longitudinal microcracks. From thehe shape of the initial area there is a turbulence of high pressure fuel flow. Fatigue stress and cracks begin at the surface of the F.O hole which is damaged due to cavitation erosion in the fuel injection system. In this section, the phenomenon of cavitation erosion is the cause of surface failure that causes cracks in the Fuel Injection Valve. The cracks are initiated by a rough surface, then the cracks spread rapidly during the loading cycle of the high-pressure fuel flow. In this case, the term cavitation appears which refers to the phenomenon of the formation of gas/vapor bubbles in the flow. When the pressure in the stream drops below the vapor pressure, bubbles are formed. If the bubble is near the solid boundary, it acts as a water hammer against the surface of the fuel injection valve. © 2025 Author(s).