ABNORMALITY DETECTION DEVICE FOR ASSIST AIR CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To provide an abnormality detection device for an assist air control device for an internal combustion engine which can judge abnormality such as deterioration of responsiveness in a control valve. CONSTITUTION:A fuel injection valve 10 is arranged on a downstream side of a throttle valve 7 in an intake passage 5. An upstream side of the throttle valve 7 is communicated with a fuel injection valve 10 through an assist air passage 17. Air is introduced to a fuel injection port of the fuel injection valve 10 through the assist air passage 17. An air control valve 18 is arranged on the way of the assist air passage 17. An assist air passage pressure sensor 20 is arranged on the downstream side of the air control valve 18 in the assist air passage 17 for detecting the pressure in the assist air passage 17. An ECU 21 judges abnormality such as deterioration in responsiveness of the air control valve 18 or blinding of the air injection port based on a pressure Pa in the assist air passage 17 detected by the assist air passage pressure sensor 20 at the time of opening and closing the air control valve 18.