What Causes the Skoda Superb to Shake at Idle Speed Inside the Car?

[ElliottMarie]

Severe carbon buildup in the Skoda Superb's engine. Most common causes of shaking: Excessive dirt in the throttle body or carbon buildup in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making ignition difficult. Under these conditions, the engine will only start easily once the carbon deposits have absorbed enough gasoline to reach saturation. After ignition, the gasoline adsorbed on the carbon deposits is then drawn into the combustion chamber by the engine's vacuum suction, making the air-fuel mixture too rich. The combustible mixture in the engine alternates between being too lean and too rich, causing idle shaking after a cold start. Adjustment method: Idle speed adjustment must be performed under normal conditions, including when the engine temperature is normal, valve clearance is appropriate, the ignition system is functioning properly, all pipelines are well-sealed, the choke is fully open, and the throttle can close tightly.