1995 passport 3.2 no spark

[89civDx]

I have a problem on my 1995 passport with a 3.2l v6. When I start the car everything is fine runs great for about 5-10 min then it starts skipping. I plug the plug wires of at the coil packs one at a time and I am not getting spark for cylinders 1 & 4. Replaced the coil pack with a new one and still have the same problem. I have changed the spark plugs and wires.