Why does the shaking at 40 exceed the non-shaking condition?

[KingLee]

40 shaking exceeding non-shaking is caused by carbon deposits in the engine throttle intake pipe combustion chamber, ignition system failure, and other reasons. Here are the specific details: 1. Causes: Carbon deposits in the engine throttle intake pipe combustion chamber, forgetting to release the handbrake, insufficient engine oil, poor quality of engine oil, excessive spark plug gap, insufficient tire pressure leading to imbalance, aging engine components. 2. Solutions: Severe engine carbon deposits, clean the fuel system, check and clean the idle motor for carbon deposits if necessary. Ignition system failure, check if the spark plugs have excessive carbon deposits, replace the spark plugs. Unstable oil pressure, check the oil pressure, replace components if necessary. Aging engine components, replace the components.