What is the reason for the Peugeot 307 shaking and stalling during cold starts?

[DelRemington]

Peugeot 307 stalling or shaking during cold starts is due to carbon buildup. Additional information is as follows: 1. Carbon deposits accumulate on the inner walls of the throttle body, the intake valve heads, the inner walls of the intake manifold, the piston tops, and the inner walls of the combustion chamber. 2. Excessive carbon deposits on the inner walls of the throttle body can cause insufficient air intake, leading to difficulty starting or stalling at idle. Once the engine reaches its normal operating temperature, the throttle opening exceeds the normal idle value, causing the ECU to repeatedly adjust the throttle valve position, resulting in fluctuating idle speeds. 3. Carbon buildup is not only common in the throttle body but also at the intake valve heads (the end of the intake manifold). 4. In non-direct injection engines, fuel is injected into the intake space where the intake valve heads are located. Residues such as gums, waxes, and unburned carbon compounds deposit here. The surface of carbon deposits is relatively loose and sponge-like.