It started this morning, idling at 2500. What happened?

It may be mainly caused by excessive carbon deposition in throttle, air intake, air intake valve and combustion chamber. Due to too much carbon and dirt in the air inlet, the cross-sectional area of the air passage changes, which makes the control unit unable to accurately control the idle intake air volume, resulting in too rich or too thin air mixture, abnormal combustion or engine jitter, and even unable to start after starting. At the same time, it is also necessary to check the working state of the fuel injector to see if the pulse width of the fuel injection is up to standard. Also use an endoscope to check whether there is too much carbon deposition in the intake valve and combustion chamber. Check the throttle idle motor, check the spark plug, check the coil and cylinder line to see if there is a lack of cylinder.