What Causes Engine Shaking and Stalling During Cold Start?

[KiraLee]

There are two main reasons for engine shaking and stalling during cold start. Below are the relevant explanations: 1. Dirty throttle body: This can cause the throttle valve to not close properly or the idle speed control motor to get stuck, both of which can lead to excessively high engine idle speed. Therefore, when the vehicle experiences shaking, the first step is to inspect the throttle body and fuel injectors. If excessive dirt is found on the throttle body or excessive carbon buildup on the fuel injectors, they should be cleaned promptly. 2. Worn engine mounts: Engine mounts serve as the vibration damping system for the engine. If there are issues with the engine mounts, it can cause shaking during idle. The engine load increases when electrical systems are turned on, leading to a drop in idle speed. To compensate for the shaking caused by this drop, the engine automatically raises the RPM slightly. When turning on the vehicle's electrical systems, especially when starting the car air conditioning in summer, the engine often exhibits shaking.