- Marine Engine:
- 3412E (S/N: 9KS1-UP; 9PW1-UP)
A decrease in RPM at wide open throttle may be noticed when replacing high hour fuel injectors with new fuel injectors on 3412E Marine Engines. 3412E Marine Engine fuel injectors with high hours may have higher than specified fuel delivery due to wear of the injector components. The increased fuel delivery occurs gradually toward end of life of the injector and causes an increase in engine horsepower.
High hour fuel injectors are injectors with 8,000 hours or more. Earlier wear to the injectors can be caused by the following:
- Poor maintenance
- Poor fuel quality
- Poor lube oil quality
The drop in RPM at wide open throttle compared to the RPM at the initial commissioning may be due to additional load from the vessel. An increase in weight or fouling of the hull can be the source of the additional load.