| 摘要 |
PURPOSE:To make a trouble judgment on a fuel system achievable without doing a road test and the discahrge test of a fuel pump single by comparing a lowering quantity of fuel pressure to be detected with a judgment reference value calculated on the basis of a driving state at that time and a fuel injection quantity. CONSTITUTION:Trouble in a fuel system C provided with a fuel injection quantity setting means B setting the injection quantity of a fuel injection valve on the basis of an output signal of a driving state detecting means A is diagnosed. This trouble diagnoser is provided with an actual fuel pressure variation detecting means I detecting a variation in actual fuel pressure in the fuel system C in particular and a reference fuel pressure variation operational means J seeking a variation reference value of fuel pressure in this system C in use of both these means A and B. In addition, on the basis of a comparison between a detected value of the mean I and a variation reference value of the means J, trouble in the system C is judged by a trouble judging means K. In brief, a fuel pressure lowering quantity reference value conformed to a racing state is calculated, and in the case where a lowering quantity in the actual fuel pressure has exceeded the fuel pressure lowering quantity reference value, a trouble diagnosis is displayed. |
