Posssibly the idle is too high. TAke the idle solonoid off of the throtle body and clean it.
I would check and see if you have a transmission or PCM problem.
Check TORQUE CONVERTER
Idle speed too high.
when u jerk it and u start
What kind of car is is? When it jerk while shutting off, do you turn the key off and it sits there chugging for a second before stopping?
Yes, because a jerk is a jerk, they would be likely to like another jerk!
Have your cat converter checked out.
It is most likely your HT leads or coil pack.
check for sticky brake calibers
Needs a new transmission. Same thing happened to my '05. Hope it's still got some kind of warranty. It's an expensive fix. $5,000+.
If you have a front-wheel-drive car, the first thing I would check would be the Constant Velocity (CV) joints.
Typically when the engine misfires it will feel like jerking. Find out why the engine is misfiring; run a computer diagnostic test and the computer should reveal the answer.