The failure of the spark plug, the high voltage wire and the ignition coil were checked, and the above three items were normal from the data of the multimeter. When starting the engine diagnostic instrument to enter the engine dynamic data and looking at the data flow, it is found that the air fuel ratio is only less than 12:1, and the signal voltage of the oxygen sensor is too low. From the signal voltage of the oxygen sensor, we can see that the problem should be in the oil supply system. So check the supply pressure, then the gasoline pressure gauge starts the engine, showing that the gasoline pressure is 280kPa, which belongs to the normal range. From this point of view, the problem may be caused by the injector being dirty, so that the throttle body and fuel injector are disassembled and cleaned. After the fuel injector is removed, all injectors have only one hole, while the normal one has four holes. Then the fault is caused by the wrong fuel injector type. After replacing the correct type of injector, the fault is eliminated.