Control system for internal combustion engine

摘要

A bypass passage for bypassing a check valve is connected with a vacuum introducing passage of a brake booster. The bypass passage is provided with a switching valve. Just before the start of an engine, the switching valve temporarily opens the bypass passage whereby to equalize a remaining pressure of the brake booster substantially becomes equal to an atmospheric level. As a result, the pressure in the brake booster at the starting time is set to substantially the atmospheric level so that the airflow to be sucked from the brake booster into the intake pipe at the starting time is made substantially contact every times. Thus, the fuel injection rate can be set considering the airflow to be sucked from the brake booster into the intake pipe at the starting time, even if that airflow cannot be detected.