What is the reason why the throttle of the car goes up and down?

First of all, consider whether the idle motor and throttle are dirty. If the spark plug is not replaced, replace it. If the fault still exists after cleaning the throttle, check the oil supply system for faults. Frequent traffic jams and bad driving habits can easily make the accelerator of the car dirty, so you should maintain the car at ordinary times, and don't wait for the car to break down before thinking about repairing it. I read about it in a magazine before. I wonder if it will help you. You can also get on the bus to help ask questions when you are free. Good luck ~ ~ ~