Check my thread about a new coil, I think the 4.0L 6 cyl mounts the coil like the 2.5L 4 cyl, on a bracket low on the side of the engine. It tough to see it clearly or fully where its mounted. When I pulled my coil, its case had numerous cracks in it and grime all over it, even though I tried to clean it several times. You really can't tell, unless you unbolt it and pull it out and look at it in good light.
A new coil solved a lot of the problems for me that people attribute to the CPS.
As well, Spark Plug Cables do wear out, they should be replaced every 60k miles, unless you have the new solid metal wire, coiled into a suppressive cable. At least check the resistance of the cables. Have someone start the motor in the dark, while you look at the motor, see sparks you know that is where your problem is. I have spotted a bad set of Spark Plug Cables once using this technique.