What is the problem with cold start shaking of the vehicle?

[Lance]

The reasons for cold start shaking of the vehicle are as follows: 1. Incomplete combustion of gasoline: The fundamental cause of shaking during cold start or idle in neutral is the incomplete combustion of gasoline in the cylinders. Poor combustion of gasoline leads to insufficient power output from the vehicle's engine, resulting in shaking. 2. Low engine temperature: Another issue caused by cold start is the low temperature of the engine, which results in low ignition energy and insufficient temperature inside the engine. This causes both fuel and lubricating oil to be at inadequate temperatures, requiring more fuel injection during cold start to meet power demands. Consequently, the gap between spark plugs increases, and the ignition energy decreases. Due to poor fuel atomization in low-temperature environments, higher ignition energy is needed for combustion. Over time, the ignition gap between spark plugs gradually widens, leading to a significant drop in ignition energy, ultimately affecting engine power and causing vehicle shaking. 3. Aging of wiring: Additionally, aging ignition coils, high-voltage wires of spark plugs, or leakage can also reduce ignition energy. Extended information: 1. Many modern engines use direct injection technology, which is prone to carbon buildup. Owners of direct injection engines are advised to clean carbon deposits every 20,000 kilometers. 2. Some auto repair shops use the "drip bottle" method to clean carbon deposits, which is ineffective. Owners are advised not to use this method. A better method for cleaning carbon deposits is the walnut shell blasting method. It is also important to avoid using low-quality gasoline, as this can cause shaking during cold start and exacerbate carbon buildup in the engine.