Why does the truck jerk when starting?

[KyleDella]

Starting, especially when the engine is cold, and experiencing jerking is usually caused by a dirty throttle body. Carbon buildup can lead to the throttle valve not opening and closing smoothly, affecting the accuracy of the air-fuel mixture parameters or preventing sensors from accurately providing feedback to the servo system. Cleaning the throttle body can resolve this issue. Below are specific causes and solutions: 1. Excessive engine carbon buildup: Cleaning the throttle body mainly addresses unstable engine idling and frequent stalling. When there is too much carbon buildup in the combustion chamber, it increases the engine's compression ratio, creating multiple hot spots that cause pre-ignition and knocking. This shortens the engine's lifespan and significantly reduces its power and fuel efficiency. Solution: Clean the throttle body. 2. Carbon buildup in the fuel injectors: This can cause uneven fuel injection among cylinders, leading to engine shaking or stalling. Solution: Clean the fuel injectors. 3. Excessive carbon buildup on spark plugs: This can cause spark plug leakage and failure, resulting in engine shaking. Solution: Clean the spark plugs.