| 摘要 |
PURPOSE:To correct the acceleration increase quantity compensation to an appropriate value at the time of starting the air-fuel ratio feedback control immediately after starting an engine by detecting the vaporization characteristic of fuel, and correcting the acceleration increase quantity compensation on the basis of a result of detection. CONSTITUTION:When the air-fuel ratio feedback control is started immediately after starting an engine (S4), the condition that the exhaust gas temperature is low or not is discriminated on the basis of the cooling water temperature Tw (S5). In the case where the exhaust gas temperature is low, a mean value alphaAV of the air-fuel ratio feedback compensation coefficient alpha (S6, S7) and a reference value are compared with each other (S8) to discriminate that the control point of the air-fuel ratio feedback control id displaced to the lean side or not. At this stage, in the case where a displacement of the control point to the lean side is detected, the fuel is discriminated as heavy fuel having a bad vaporization characteristic. |
