2001 Mustang V6 all stock I just bought is shaking and jerking bad at Idle and up to around 20 MPH then it seems to run smooth, the car doesn't seem to have a lot of power but im assuming its because its the V6. Any idea's what would cause the jerking? Im thinking spark plugs or fuel pump/filter but im kinda new at this. Thanks

 

Is it missing? Put your hand over the exhaust pipe and it should feel relatively smooth and consistant, if it is not it is probably missing. Replace the plugs (wires too if they look old) and it it continues preform a cylinder balance test. Pull one injector off at a time, and the one that did not make it run worse is your bad cylinder (probably bad injector or wiring)

 

Does it shake sitting still, or only when moving? Sitting is a missing cyclinder, rolling could be wheel/tire issue.

 

I guess the right term is bucking, like someone keeps bumpin into the back of the car throwing me personally back and forth, does it while sitting still and driving at low speeds, up to about 20 mph then it seems to go away until. Stop at another light or slow down for traffic

 

Then it comes back, hit post too soon lol

 

Sounds like you probably have a miss that needs to be resolved, probably plus and wires, etc.

It's also possible that you have a broken motor or transmission mount that is exagerating the effects. Check all of your isolators for tears and tune it up.