A 2009 DF Honda 2.4L CRV with a mileage of about 103 thousand km. Car owner Description: this car starts normal when hot car, cold car starts difficult. Maintenance summary: this car is due to the poor quality of the fuel filter core, the existence of pressure relief in the process of use, resulting in a period of time after the shutdown of the fuel oil pressure is too low, causing the vehicle to start difficult to start trouble. There are many reasons that cause the vehicle to be difficult to start. We should pay attention to the following points for the maintenance of such failures. 1. to reappear the failure phenomenon. This allows us to identify the probable cause of the failure so as to correctly lock the inspection area. 2. the inspection should be easy to be difficult, the first power after the machine. This can avoid a great deal of effort and a lot of time to find out a very simple fault. 3. be good at communicating with the owner of the car. This helps to troubleshoot faults and avoid detours, thus saving time and finding fault points as soon as possible. 4. the use of instrument and equipment is combined with the idea of diagnosis. Only when we are good at using the equipment correctly can we determine whether there is any fault in the inspection items. Only when we are diligent in thinking, can we have a clear way of thinking. After troubleshooting and troubleshooting, the vehicle is started without abnormal detection. After parking about 30min, turn the start key, 7 to 8s to start the fire. After starting, the engine operates normally, and the road test is normal. Using HDS to detect the vehicle, no fault code. Viewing the data flow can determine that the water temperature sensor of the vehicle is normal, and the start-up difficulty is independent of the water temperature sensor. Check the EGR valve, normal. The battery voltage is detected by the multimeter: the battery voltage is 12.1 V when parking, and the minimum voltage of the battery is 11.3V in the starting operation, and the battery voltage is 14.2V after the vehicle is started. It can be concluded that the battery is in good condition, and the difficulty of starting the vehicle is independent of the battery. Check the throttle, there is no obvious dirt; check the pipeline, no leakage; carry out the oil pressure test, normal. Is it a nozzle blocking? But, after viewing the car, the car is well maintained. Has the car ever had an accident or had it been disassembled? By communicating with the owner, it was understood that the car was a difficult time before it was repaired at the roadside repair shop. During maintenance, throttle cleaning, oil path cleaning and fuel filter replacement were carried out. No collision accident occurred and no nozzle was removed. What causes the vehicle to start? It is the difference in the fuel filter core.