2004 SE jerks real bad

My wife has a 2004 Freestar SE and it jerks real bad going down the road. The coil pack has been replaced and the fuel filter has been replaced. The plugs and wires aren't too old but I don't think it's that. Does anybody have any clue as to what it could be? It's also lost a lot of it's power also.

My wife said that under 55 MPH is when it jerks the worst. Can somebody please tell me what's going on with her van? I'm honestly getting tired of having to do this and that to it.

I don't have this issue on mine. Also are you getting a CEL. Check Engine Light.. If the coil has been replaced check the wires to make sure there snapped in good. Was the CEL on before you changed the coil. Also is the coil a Motorcraft or aftermarket.? Gary

The engine light was on before I replaced the coil pack. And the coil pack is a Motorcraft straight from the Ford dealership. I've thought it's a fuel injection problem somehwhere. I've thought about replacing the TPS sensor and checking to see if one of the injectors might be bad or something. In my opinion you'll be driving down the road and if you take your foot off the gas and just like idle down the road it's fine runs great and everything. But when you resume throttle it's jerks and vibrates and everything and lost all kinds of power going up hills. Does anybody have any clue what could be this problem?

The only thing I could say is to check out the TPS or the VSS or wait until the check engine light comes on and see what codes.. I was unable to find anything about this..

I've thought more than a few times about the TPS sensor but I've never head of the VSS....what is that? Thank you a lot for checking in for me I appreciate that a whole lot. Could it be any or all of the O2 sensors?

VSS is vehicle speed sensor. If it has needed a coil pack you have enough miles on it to need spark plug wires. They fail at their worst under a load. If you think it is an injector problem run some cleaner through a tank of gas. Make sure your battery terminals are clean and tight. Is it still under warranty? Don't think it would be an O2 sensor. When they fail they usually make the engine run too rich. You would be getting a CEL if the O2 sensor was bad. Sure sounds like an ignition problem. I had a Corvette that did exactly what you describe. It had water in the tank. Being heavier than gas it got in the pickup. I put some HEET in the tank to absorb the water and it ran good after that.

Last tank of gas she put in I put in some Lucas Fuel treatment and that seemed to work a tiny tiny bit but now it's back to itself again. My check engine light is on and flashes too. I guess I'm gonna do an ignition improvement and see what happens.

Last tank of gas she put in I put in some Lucas Fuel treatment and that seemed to work a tiny tiny bit but now it's back to itself again. My check engine light is on and flashes too. I guess I'm gonna do an ignition improvement and see what happens.
Flashing!!! I wonder if you got a dud coil. I know the ford dealers love too sale them.. HMMMM I worked on a Ford Explorer and got a dud coil. I about lost my marbles.. Called Ford they told me to bring coil back. It worked fine with replacement.