Study on Optimization of Control Parameters for the Second Cycle during Forward rotation direct-Start Process at a GDI Engine

摘要

To get better starting performance for GDI engine forward rotation direct-starting without starter, the optimized choices of fuel injection and ignition control parameters under different initial start conditions was carried out in a wall-guided GDI engine. The results showed that the ignition timing and injection timing have been less affected by the initial start conditions. When the ignition timing is kept near its compression TDC and the injection timing is kept within the scope of 2-10°CA after the crankshaft rotation, the engine all can get higher rotation speed under different initial start conditions. When the fuel pressures and cooling water temperature are lower, the richer mixture was needed for obtaining higher rotation speed.