Is it normal for a car to shake when starting after releasing the brake?
1 Answers
It is not normal for a car to shake when starting after releasing the brake. The specific causes and solutions are as follows: 1. Engine carbon deposits: Severe carbon buildup is the most common cause of car shaking, often due to a dirty throttle body or excessive carbon deposits in the fuel injectors. When there is too much carbon inside the engine, the gasoline sprayed by the fuel injector during a cold start will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture and making it difficult to start. In this situation, the car will only start easily once the carbon deposits have absorbed enough gasoline to become saturated. After starting, the gasoline adsorbed on the carbon deposits will be drawn into the combustion chamber by the engine's vacuum, making the air-fuel mixture too rich. This fluctuation between lean and rich mixtures causes the engine to idle roughly after a cold start. Additionally, the lower the temperature, the more fuel is required for a cold start, and the presence of carbon deposits will further affect the smoothness of the cold start. The solution is to clean the fuel system and check if the idle control valve has carbon deposits that need cleaning. 2. Ignition system issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance in the ignition system or weak sparking from the spark plugs can also lead to this type of problem. The solution is to check if the spark plugs have excessive carbon buildup and replace them if necessary.
