The car will shake a few times when it refuels. What's the matter?

When the ignition is insufficient and the oil-gas mixture is strong (when the accelerator is stepped deeply), the spark intensity is insufficient and the intake speed is slow, resulting in insufficient combustion only near the spark. However, after the speed comes up, the intake speed is fast, which obviously relieves the symptoms. The solution is to replace the cylinder line spark plug, and other carbon-deposited nozzles block the throttle and dirty the clutch pressure plate, which is not a positive solution.