None of the solutions to the problem with the "intermittent miss" seem to lead to a definitive answer. I am going through the same set of symptoms right now and have done all of the proposed fixes, to no avail. With the exception of the "Torque converter shudder". (That one seems a little off the wall). Changing the plugs, plug wires, and coil didn't bother me as those were more in the line of routine maintenance.
I will continue to monitor this thread in the Freestar forum in case someone does stumble on to the solution as it is aggravating.
A related question: Has anyone else had trouble with breaking the plastic tabs off of the upper cowl while removing it to get access to the back side of the engine? Those fasteners were not very well engineered, but a little epoxy cured that problem.
My thanks to all who post here. I have learned more about my Freestar here, than from all of the local service departments combined.

 

Just a reminder-----------
The wires that go from the coil to the plugs don't follow a simple sequence and it might be a good idea to recheck their positions especially #5 & 6.

 

I experienced the same symptoms, miss at easy throttle, comes and goes. I had changed the plug wires and plugs and it helped some but the miss at slow speeds when easy throttle applied never completely disappeared. I felt like I had enough money invested that I might as well eliminate the rest of the ignition system so I ordered a new coil. Four days later with the same symptoms apparent each time that I drove it, I installed the new coil. Driving it the first time I felt like I had inherited a new car. More pep at easy throttle, silky smooth shifting, and even quieter exhaust. Loving the results, but still thinking that part of it might be just my imagination, I reset the Average MPG Indicator to "0"when I went out the gate yesterday. After about 70 miles of combined Interstate and surface street driving I came back to the front gate with the meter reading 21.1 MPG average. Prior to this I had never gotten above 17.8, even on the highway.
A new after market coil cost me $28.85 on eBay. (10yr warranty). Best money I've spent in a long time.
The actual changing of the coil is a whole 'nuther posting!!!

 

Already tried that. No effect whatsoever...

 

60DRB, can I ask where you obtained the coil and what brand was it?
Did you check all the ground connections? Folks who overlook the basics depend on computer codes and not all intermittent problems throw a code/codes.
Not to get you going out and replacing a lot of parts, but a crank sensor that has a poor connection will not always throw a code and neither will a throttle position sensor that has a "flat spot". These problems can drive a tech up the wall unless he/she has a scope to catch those little glitches and you may need to have a shop with good scope experience chase the problem down.
A tired motor mount may just allow the engine to shift enough to create an intermittent wire contact and produce a problem so as you can see no codes doesn't mean there is no problem.

 

Coil from Ford. I've been all under the vehicle and looked at everything I could see, for any loose items, connections, grounds, etc. Opened plug connections looking for corrosion, and applied dielectric grease when reconnecting them. It's a pretty clean vehicle in the engine area and underneath.

"a scope"?... What exactly are you talking about? A diagnostic machine/device?

Finding a savvy tech has proved harder to find than the cause of the problem. I did discover the Ford shop failed to properly reassemble the air cleaner box or attach the hose clamp to the throttle body. MIL let the shop replace the spark plugs and air filter the last time she had the car in for this problem. They just make things worse it seems.

 

You aren't the first and won't be the last customer that might have had the new inexperienced tech work on their vehicle. Just like there shouldn't be some doctors in the medical field there shouldn't be some people in the automotive repair field and most of us have come across them at one time or another.
The "scope" I referred to is called a digital storage oscilloscope. It permits the tech to observe a visual picture of the electrical happenings in a circuit. It can capture glitches that a meter would miss . It is the tool of choice when we have problems such as your vehicle seems to exhibit. An experienced tech can use this tool very effectively and save a lot of time and trouble. I would almost bet your Ford dealer shop has one ,but the service writer or the service manager possibly did not think one of their best service person(s) was required to correct the problem. You need to impress on them the need to get this corrected since this is the second time you are bringing it back. There is a charge for just diagnostic time and it varies from shop to shop. Expecting that should help soften the blow of the bill , but if the problem is annoying enough it will be worth it.

 

Well update, took it back to the dealer for a recheck. And sure enough bad torque converter. The service manager said that was the first bad replacement converter they have had. Don't believe them, but at least they are going to replace and fix for free for the second time.

Thanks for everyone's help and input. One thing down and a few more things togo to fix/replace.

Whats everyone's opition on how to replace a rack and pinion on a 2004 freestar the easiest? It started acting up some.

 

She's actually had the car in 4 or 5 times for this problem. I'll give her a print-out/written explanation of what equipment to have them use next time she takes it in. Thanks for the information.

 

A couple days ago her car started the (as yet unidentified) jerking again, the the engine died. She was able to coast to the roadside. She said the battery and oil lights were on, and after stopping on the roadside she was able to restart the car an drive home.

The alternator was replaced about two years ago, and the battery about two and a half years ago. She hasn't been able to get to a shop yet.