The engine of my Chang 'an Jinniuxing van 474 is hot-started, and it can't afford to add oil, oil pump, throttle, computer board, spark plug, oil nozzle and high-voltage cable package.

Water temperature sensor failure. The water temperature sensor has two functions: one is to report the engine temperature to the computer, which is used to calculate the fuel injection quantity under different working conditions; Another water thermometer reports the water temperature information of the engine to the driver. Therefore, on some engines, there are two water temperature sensors or one sensor connecting multiple pipelines.

The water temperature sensor on your engine reports the wrong water temperature information to the computer. The ambient temperature is already very low. It reports the starting signal of normal temperature or hot car. The computer calculates and executes fuel injection according to the error signal, and the mixture is lean. In addition, the oxygen content per unit mass is low at air temperature, and the mixture is not easy to burn and start. When the cold car was idling, the computer also executed the wrong fuel injection quantity, so it idled at the bottom. When the engine is hot, the error signal value reported by the water temperature sensor coincides with the actual value of the engine, so everything looks normal.

Under normal circumstances, when the ambient temperature is low, the engine computer receives the low-temperature start-up signal from the water temperature sensor, and the calculation of relatively rich mixture is beneficial to the low-temperature start-up, and the idle speed of the cold car is controlled to be higher than the usual idle speed, thus achieving the purpose of quickly warming up and reducing harmful gas emissions.