The Sonata Nine Cooler started upright. What's going on here?

Generally, the first thing to do when idling is shaking is to distinguish whether the idling speed is too low or the cylinder is missing. If the idle speed is too low, you can clean the idle valve and throttle. If not, check the data flow with a computer to see if there is anything wrong with the air inlet. If the cylinder is missing, it is necessary to overhaul the fuel injection system, ignition system, cylinder pressure and timing!