Air-fuel ratio control method that reflects the air inflow rate from the brake booster

摘要

PROBLEM TO BE SOLVED: To provide an air-fuel ratio control method capable of improving the accuracy of control by reflecting fresh air flowing from a brake booster 4 into an intake manifold 13 in air-fuel ratio control when controlling the air-fuel ratio. With the goal. SOLUTION: When a deviation occurs between an actually measured pressure of the intake manifold measured by a MAP sensor and a model pressure of the intake manifold using a measured value of an air flow sensor, whether or not the deviation is a deviation generated by a brake operation. If the deviation is the deviation generated by the brake operation, the intake air amount is corrected by reflecting the flow rate flowing from the brake booster into the intake manifold, and the air-fuel ratio control is performed based on the corrected intake air amount. When it is determined that the deviation is not the deviation generated by the brake operation, the air-fuel ratio control is performed with the inflow air amount by the brake booster set to 0. [Selection diagram] Fig. 2