Lifan 620, the throttle has been cleaned with oil.

The throttle needs to be re-matched after cleaning, otherwise the idle speed will be high. Because there will be impurities in the intake process for a long time, these impurities will accumulate at the throttle for a long time, and then more and more carbon will be deposited. When the throttle valve reciprocates, it will be resisted for a long time, so the engine computer will adjust the position of the throttle valve. That is to say, the position of carbon deposition is regarded as the ontology, that is to say, the throttle valve is not at all but near the position of carbon deposition. After the vehicle cleaned the intake valve, the flap still moved in the original formation, which showed that it was not in place, but the carbon deposit was cleaned. So the air intake will be a little more than usual. This will lead to high idle speed. In this case, computer programming is required. If you don't do it, the engine computer will take a long time to adjust and recover.