The Design And Experiment Study Of Electronic Fuel Injection System For Motorcycle Engine

With the increase of environmental protection consciousness and implementation of energy saving and emission reduction policy which is being promoted by the government, the fuel economy and emission of motorcycle engine have become significant indexes for the technical competition of motorcycle producers. In order to meet the stricter emission law and regulations, the traditional motorcycle engine with carburetor system will be inevitably retrofitted by electronic fuel injection (EFI) technology.The overall control scheme of EFI system was determined by summarizing both the domestic and abroad state-of-the-art development of motorcycle engine, and also by comparing the characteristics of different EFI systems while the actual situation being fully considered. The LY172MM motorcycle engine was studied and an intake manifold fuel injection system was designed to replace the original fuel supply system with carburetor, and meanwhile, the matching of intake air system and fuel injection system was carried out.An improved open-loop electronic control system for low cost motorcycles was presented in this thesis. The MAP of electronic control system under steady working conditions was calibrated according to theoretical A/F ratio based on the fuel injection MAP of motorcycle engine with carburetor system. Furthermore, the test bench was installed, and the performance of motorcycle engine with EFI system was tested. As indicated by the test result, the fuel consumption of motorcycle engine with EFI system is considerably lower than that with carburetor system, and the output power was increased under part load condition.