What Causes Engine Shaking and Stalling During Cold Starts?

[AbigailRose]

If the engine shakes a few times and stalls during a cold start, it indicates that the engine shows signs of starting but fails to run successfully. The likely causes of this issue lie in two aspects: electrical sparks and the air-fuel mixture concentration. Below is the relevant information: 1. For an engine to start normally, it requires strong and properly timed electrical sparks, sufficient cylinder pressure, and an appropriately concentrated air-fuel mixture. Carbon buildup on the spark plugs can reduce the spark plug gap, thereby lowering the voltage required to generate a spark. In this case, the spark energy is insufficient to ignite the air-fuel mixture. During engine startup, the battery supplies power to the spark plugs, and insufficient battery voltage can also lead to inadequate spark energy. 2. The ignition timing of the engine is controlled by signals received from the camshaft sensor and the engine ECU. Generally, the ECU program does not malfunction, so a faulty camshaft sensor is a more common cause.