After cleaning the throttle nozzle for a few days, the car is difficult to start.

There are many reasons for poor engine start, and the analysis is as follows: engine failure, such as air leakage in the intake system, insufficient gasoline engine oil pressure, damaged parts, etc. The poor quality of gasoline leads to carbon deposition on the back of the intake valve, while the fuel nozzle of the injection system directly sprays gasoline on the back of the intake valve. During the cold start in the morning, the carbon deposit was completely dry. At this time, just like a sponge, the absorption of gasoline leads to a temporary shortage of oil, so the engine will shake or even turn off, but it will be better or completely normal after restarting. According to your description, it may be bad oil or insufficient oil pressure. It is recommended to check the oil pump.