Camshaft Postion Sensor (CPS) location.
http://rides.webshots.com/photo/2804...11220610IkRBFJ
I have it labeled "cps" in yellow print in the picture.
Things around it may look a bit different.....as this is my '96 3.8L......but yours will have the CPS in the same location.
You can click on the "+" in the bottom right corner of the picture to zoom in so that you can see more detail.
Zoomed in, you will see 2 small bolts on the TOP of the nylon body of the CPS.
These are the ONLY bolts that you should remove when changing the CPS.......as well as unplugging the electrical connection.
The bolts down by the shaft.....at the base of the mount should NOT be touched, as this will result in problems getting it lined back up correctly.
In short.....the CPS is Easy to change.
As far as spark......the coil pack contains 3 coils.......each coil secondary winding fires 2 spark plugs.
The primary coils are driven DIRECTLY by the PCM (computer) on the Windstar......
The PCM provides a ground path for 1 end of the primary coil......and the other end of the primary coil is connected to +12 volts.
The fuel injectors are driven the same way......1 end of the coil in each fuel injector has +12 whenever the ignition key is ON......and the other end of the coil in each fuel injector connects to the PCM.....and the PCM provides a momentary ground to energize the fuel injector.....giving the correct sqirt of fuel.
It IS worth checking to see if you have fuel pressure at the test point at the middle of the front of the fuel rail.
The fuel pumps have been known to fail....
Of course.....a good fuel filter is a must.......
If the battery is weak.....it might drop down in voltage when you crank the motor......and not have enough voltage to keep the fuel pump running.
Fuel problems are common.
Total loss of spark is not real common (loss of spark to one or 2 cylinders is not uncommon).....which is why folks have mentioned the fuel system.
I have reminded you....but I am guessing that you have done some test to make certain that you do not have spark.....and not just guessing.....and want to give you a "what to check next" in case plan "A" does not work.
But....in case you find that you do have spark.....and it is not starting......next step would be to verify fuel pressure.
I have most likely given more explanation than needed....but I am trying to make the explanation help others who read this post.