The Development And Research Of Idle Control For EFI Motorcycles With FAI Technology

Gasoline and diesel are main fuels for automotive and motorcycle engines. As well as the developing of the industry and economic, the requirement about fuels will be much more than the supply. How to save energy and control the exhaust emissions while improving engine performance are the main topics people caring about. Meanwhile, the idle control process is very important in motorcycle control. It relates with engine stability, exhaust emissions and fuel consumption performance. Under this condition, the application of electronic control technology in motorcycle control especially in idle control is very important. Therefore, the idle control system based on FAI's EFI system is the main research issue in this paper.First, the over all designing of the idle system was introduced. It also explains the control methods of motorcycle idle control. After that the advantages and reasons of choosing MCU, idle valve and other parts in the ECU were also explained. After that some control ways that used commonly in motorcycle idle control are also introduced.Second, basic construction of the motorcycle's ECU is described, including every part of the ECU, and its difference compared with automobile. It also explains the EMC designing of the ECU, and the software designing of idle control. To improve the performance of idle control, the idle process divides into three small processes: cold boot process, warm process and stable idle process. Based on different control character and aim of the three processes, different idle control strategies are adopted. The amount of fresh air through idle valve is also revised base on the cylinder header temperature, battery voltage and other parameters. The change of fuel amount is close related to the change of air amount. When the air and fuel ratio is 14.7 and the oxygen temperature is enough, the close loop control was used in the idle control.Finally, through lots of experiment, above idle control method is verified and the best idle control method for FAI's EFI motorcycle is achieved. These experiments also prove that the idle control system is useful and effective for improve engine idle performance.