| 摘要 |
PURPOSE:To obtain a proper air-fuel ratio promptly, for instance, at the time of decelerating operation of an engine, by interrupting feedback correction of the air-fuel ratio in case that the required injection quantity of fuel is smaller than a reference injection quantity in the neighbourhood of the minimum injection quantity determined by the minimum valve opening period of an injector. CONSTITUTION:According to the control method of this invention, the fuel injection period is calculated in an ECU40 on the basis of the oututs of a crank-angle sensor 36 and a sensor 22 for detecting the pressure in an intake pipe, and a new, required injection period is calculated by multiplying the fuel injection period by the already calculated, previous feedback correction factor that is determined by the deviation between a reference air-fuel ratio and the actual air-fuel ratio. Here, judgement is made whether or not the required injection period thus calculated is smaller than the minimum injection period dependent on the minimum valve opening period of an injector 26 that is predetermined by way of simplex evaluation or the like. In case of YES, feedback correction of the air-fuel ratio is interrupted for preventing the air-fuel ratio from becoming over-lean temporarily. |
