A TOYOTA car with a mileage of about 160 thousand km. User response: the starting time of the vehicle is significantly longer than that of other vehicles. To the 4S store warranty, when the car was confirmed, it was found that both in the cold car or the hot army all have the above phenomenon, and must pass through two consecutive starting to grudge the car, starting time above 6S. According to users, in addition to this fault, there is also accompanied by the phenomenon of slow acceleration. Fault analysis: using the detection instrument for diagnosis, the results show no DTC (fault code), but the idle speed of data flow shows, the long-term fuel correction value is up to 12.2%, and as the load increases to 20.6% near, indicating the existence of the presence of mixed gas image. The fuel correction value increases with the increase of the load. It is very obvious that the fuel supply system of this vehicle is abnormal. Combined with the phenomenon of too long starting time reflected by the user, the following conclusion can be obtained preliminarily: the oil pressure supply and maintenance of the vehicle may be in problems. For further analysis, the fuel pressure is first measured, then the fuel pressure gauge is connected to the oil circuit to test again, and the correlation between fuel pressure and fault phenomena is observed. The test results show that the oil pressure is only 290kPa when the engine is working normally, slightly lower than the standard value (310 ~ 350kPa), and the oil pressure drops rapidly to 0kPa after the quenching, and no residual pressure can be maintained. Because the car's fuel line is no loop control, there is no leakage in the external pipeline, so it can be presumed that the failure of the oil pressure of the engine should be in the fuel pump and oil pressure regulator, and because the fuel pump and oil pressure regulator of the car are integrated on the fuel filter in the fuel tank, so the car's fuel pump and the oil pressure regulator are all integrated on the fuel filter in the fuel tank. Dismantling it. It is found that the clamps of the fixed fuel pump and the oil pressure regulator are removed from the cartridge case of the fuel filter, resulting in the downward displacement of the fuel pump under the action of the oil pressure, which makes the sealing ring of the fuel pump out of the oil outlet misplaced, resulting in the oil outlet pressure relief and the failure of the oil pressure to keep the engine after the engine is extinguished. Troubleshooting: reassemble fuel pump and fuel filter cartridge. Failure revelation: Although this is a man-made fault when the vehicle is out of the factory, it is very helpful to analyze the corresponding relationship between the fuel correction and the fuel supply when the fuel correction value is changed, according to the phenomenon of the fault and the full use of the measuring data of the detector and the oil pressure meter, and the corresponding relationship between the fuel correction value and the fuel supply. Fault comment: This is another man-made fault, I hope you can reflect more.