21. Study of Start-Stop Technology on a GDI Engine

This paper has developed a start-stop control system on a GDI engine, studied effects on the rate of ignition for expansion cylinder and the start-stop performance without a starter. The experimental results showed a total rate of a successful ignition of the expansion cylinder beyond 70% when the lambda value ranges from 0.6 to 0.7. A multiple fuel injection could improve the rate of ignition with the case of single injection compared, the rate of ignition can be increased by averaged 4% for two times fuel injection, a four times fuel injection can increase the rate of ignition by averaged 5%. When the exhaust valve opening timing was retarded to 160 °CA ATDC increased success rate of engine starting. It will be 0.62 s for engine start by a start-stop starter, however 0.39 s by direct injection start-stop.