2002 Ford Winstar runs jerky at any speed and at acceleration on 2002 Ford Windstar

When in gear the van seems to want to jerk forward. The tacometer doesn't move so it might not be the engine....could it be the transmission? When I drive it at any speed it feels like I'm getting bumped from behind like in a nascar race. When I put the pedal to the floor I do have speed, but it does seem to have hesitation to get up and go. WHAT IS GOING ON????

I had a similar problem. It was a bad coil pack.