Scheduling Injection Timing for Reduction of Diesel Emissions

This paper deals with the requirements for scheduling injection timing as a function of speed and load for high-speed light-duty diesel engines and also for larger diesel engines. A combined speed and load timing device developed for the CAV DPA pump is presented. Work on two passenger cars powered with swirl chamber diesel engines initially having standard DPA pumps and later fitted with pumps incorporating the timing scheduling device is then described and discussed. Some examples of timing scheduling requirements for larger direct injection engines are also given. It is shown that injection timing scheduling is essential to minimize gaseous and visible emissions while satisfying the noise and fuel economy aspects of engine or vehicle performance.