What Causes Shaking During Acceleration?

[LaReagan]

The causes of shaking during acceleration are: 1. Poor fuel delivery: Insufficient fuel supply at low throttle causes uneven operation of engine cylinders, resulting in shaking; 2. Dirty throttle valve: Uneven intake airflow leads to shaking; 3. Broken or burnt high-voltage wires or spark plug failure causing some cylinders to misfire, making engine operation unstable and resulting in shaking. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold-start injector can be largely absorbed by the carbon deposits, leading to an overly lean air-fuel mixture during cold starts and making it difficult to start. In this situation, the engine can only start easily after the carbon deposits have absorbed enough gasoline to reach saturation. Once started, the gasoline adsorbed on the carbon deposits is drawn into the cylinders by the engine's vacuum suction and burned, making the air-fuel mixture too rich. The fluctuating air-fuel mixture (alternating between lean and rich) causes idle shaking after a cold start.