Q: Jerking forward at a full stop.

This may be related to a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. As this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. In your case the idle air control valve may be misreading the load and relaying that it needs more fuel to the computer which then supplies more fuel than needed resulting in the forward lurching reaction. I would recommend having an expert from YourMechanic come to your location to诊断和修复空闲的空气控制阀。