Why does the car jerk when warm but not when cold?

[JeremiahMarie]

It may be due to low temperature issues. When the engine is not warm enough, more fuel is injected during cold starts to meet power requirements. Below is relevant information about car idling: 1. The function of car idling: Idling is an operating condition of a car, referring to the engine running in neutral gear. The engine speed during idling is called idle speed. Idle speed can be adjusted by modifying the throttle opening size. Idling means the engine is "producing power without doing work." When the engine is running, if the accelerator pedal is fully released, the engine is in an idling state. 2. Reasons for unstable idling: Direct causes refer to mechanical components being dirty, worn, or incorrectly installed, leading to changes in cylinder power output, resulting in unbalanced power among cylinders and causing unstable engine idling; Indirect causes refer to abnormalities in the engine's electronic control system, leading to poor combustion of the air-fuel mixture, making it difficult to balance power among cylinders and causing unstable engine idling.