| 摘要 |
PURPOSE:To make it possible to carry out combustion of lean mixture due to stratified burning in a wide range, by providing such an arrangement that the initiation timing of fuel injection by a fuel injection valve is set in a substantially later half of the intake-air stroke and the termination timing thereof is set at the termination of the intake-air stroke, in a predetermined engine operation range. CONSTITUTION:Upon engine operation, a CPU 10 determines whether the basic fuel injection amount which has been computed in accordance with the outputs of an intake-air pressure sensor 12 and a crank angle sensor 22, is greater than a set injection amount or not, and when it is less, controls the pressure of fuel. That is, a duty ratio is read out from a map in a memory in accordance with the basic fuel injection, and an ON-OFF valve 9 is controlled in accordance with the duty ratio by means of a fuel pressure control circuit 21. After an injection time period, as a fixed time period, is set to an injection timing control circuit 19, the value which is obtained by subtracting this fixed time from a required time for intake-air stroke, is set as the injection initiating timing. When this injection initiating timing is detected, fuel injection is made from injectors 5. |
