| 摘要 |
PURPOSE:To stabilize a changeover state of an engine upon its transient operation by correcting ignition timing in responce to the delayed operation of a changeover valve provided in a secondary side air intake device at detecting said transient operation. CONSTITUTION:In the operation of an engine 1, a basic fuel injection amount is read out based on outputs from a number-of-revolutions sensor 18 and a negative pressure sensor 19, and thereafter it is corrected for water temperature, and for acceleration and deceleration. Then, a lead angle reference value thetao of ignition timing from a lead angle map based on said number of engine revolutions and air intake negative pressure, while a lead angle thetat corresponding to a target valve opening of a changeover valve 16 read out based on the operation state at that time is read out. In addition, a lead angle thetar corresponding to an actual changeover valve opening is read out. Both of said lead angle values are subtracted to evaluate a delayed amount thetas. The reference value thetao, water temperature correction value thetaw and delayed amount thetas are added to yield an actual lead angle theta. Based on this lead angle theta, ignition timing is controlled. |
