| 摘要 |
PURPOSE:To diagnose whether changeover control of supply/sht-off of assist air actually functions and expected control of atomizing fuel normally functions or not by diagnosing the trouble of the assist air device based on the changing condition of an intake air flow. CONSTITUTION:An intake air flow detecting means is constituted so that an air flowmeter 8 is provided in an intake duct 3, and a signal according to the intake air flow of an engine 1 is output. An assist air passage 15 is provided so that it is branched from the intake duct 3 on the upper stream side of a throttle valve 4 and is opened in the vicinity of the nozzle of of each fuel injection valve 6, bypassing the throttle valve 4. A usually closed type solenoid valve 16 controlling opening/closing the assist air passage 15 ON/OFF likely is controlled to be ON/OFF by a control unit 12, based on the information of a water temperature sensor 10. The control unit 12 is provided with functions as an intake air flow changing condition detecting means and a self-diagnosis means as the software. |
