| 摘要 |
PROBLEM TO BE SOLVED: To provide a malfunction diagnosis device for a cylinder injection type internal combustion engine, enabling to minimize an erroneous diagnosis resulting from fuel dilution for lubricating oil due to the deposition of fuel on the inner peripheral face of a cylinder when diagnosing the malfunction of a fuel injection system in accordance with an air-fuel ratio correction amount for air-fuel ratio feedback control. SOLUTION: An electronic control device 50 calculates the air-fuel ratio correction amount for the air-fuel ratio feedback control in accordance with a tendency of deviation between an actual air-fuel ratio and a target air-fuel ratio and determines the malfunction of the fuel injection system in accordance with the air-fuel ratio correction amount. The electronic control device 50 estimates a degree of fuel dilution for whole lubricating oil supplied for lubricating the internal combustion engine 10 in accordance with the history of cold short trip. The electronic control device 50 prohibits the determination of malfunction on condition that the degree of fuel dilution is high. COPYRIGHT: (C)2008,JPO&INPIT
|
