Optimizing the fuel injection system of marine diesel engines is critical for improving overall efficiency and minimizing troubleshooting issues. This paper explores the key parameters of the fuel injection system, such as fuel injection timing, pressure, and nozzle efficiency, to enhance fuel combustion and engine performance. By optimizing these factors, the system can achieve better fuel economy, lower emissions, and extended engine life. The study also incorporates preventive maintenance strategies to detect and resolve potential issues before they escalate, ensuring smoother operation and reducing downtime. The overall goal is to improve the efficiency and reliability of the marine diesel engine through a comprehensive evaluation and optimization of its fuel injection system. The baseline emissions increase steadily from 155 grams/hour in 2014 to 200 grams/hour in 2024, reflecting a continuous rise in CO2 emissions over time. The optimized emissions are consistently lower than the baseline but follow a similar upward trend, starting at 155 grams/hour in 2014 and reaching 200 grams/hour by 2024. For NOx baseline emissions decrease gradually from 50 grams/hour in 2015 to 45.5 grams/hour in 2024, a modest 9% reduction. In contrast, optimized emissions drop significantly from 50 grams/hour to 32 grams/hour in the same period, achieving a 36% reduction. This highlights the effectiveness of optimization strategies in reducing NOx emissions, suggesting they are crucial for achieving better environmental outcomes and regulatory compliance. Particulate emissions (g/h) from 2015 to 2024 under baseline and optimized conditions shows that baseline emissions decrease from 10 g/h in 2015 to 8.2 g/h in 2024, while optimized emissions drop more significantly, from 10 g/h to 5.5 g/h over the same period