There are significant differences between electronic fuel injection diesel engines and direct injection diesel engines in terms of fuel injection mode, technical characteristics, fuel efficiency, emission performance, and maintenance.

　　1. Fuel injection method

　　Direct injection diesel engine: Injecting fuel directly into the combustion chamber simplifies the mixing process of fuel and air, but places higher demands on injection technology and combustion chamber design.

　　Electronic fuel injection diesel engine: It adopts an electronic control fuel injection system, which accurately controls the injection quantity, injection timing and other parameters through sensors, ECU (computer) and actuators, achieving fine adjustment of fuel injection. This method can more accurately control the air-fuel ratio and optimize the combustion process.

　　2. Technical features

　　Direct injection diesel engine: The technology is relatively simple and the cost is low, but the combustion efficiency and emission performance may be limited to some extent.

　　Electronic fuel injection diesel engine: With more advanced technology, it can achieve accurate control of the fuel injection process, thereby improving fuel efficiency and emission performance. At the same time, the electronic fuel injection system also has fault diagnosis and self-protection functions, improving the reliability and safety of the diesel engine.

　　3. Fuel efficiency and emission performance

　　Direct injection diesel engine: It may be slightly inferior to electronic injection diesel engine in terms of fuel efficiency and emission performance, as its injection process is limited by mechanical structure and fuel pressure factors.

　　Electronic fuel injection diesel engine: By accurately controlling parameters such as fuel injection quantity and timing, it can achieve more complete combustion, thereby improving fuel efficiency and reducing emissions.

　　4. Maintenance and upkeep

　　Direct injection diesel engine: Due to its relatively simple structure, maintenance is relatively easy, but it may require more frequent cleaning of components such as the combustion chamber and fuel injectors to remove carbon deposits.

　　Electronic fuel injection diesel engine: Maintenance and upkeep are relatively complex, requiring regular checks on the working status of sensors and actuators, as well as necessary calibration and replacement. However, its high-precision control system also helps reduce the probability of faults occurring.

　　Overall, there are significant differences between electronic fuel injection diesel engines and direct injection diesel engines in multiple aspects. When making a choice, it is necessary to comprehensively consider factors such as specific usage needs, cost budget, and emission requirements.