Had a whole bunch of fun this weekend. I had an ignition miss. My CoPs were long overdue change, 7 were original equipment and 3 unknown brand replacements. I installed Denso coils after reading old threads to decide on which brand to use. Replaced 10 CoPs, 10 fuel injector electrical connectors and 9 CoP electrical connectors. I just couldn't bring myself to endure the busted knuckles and cussing that would surely have taken place if I had tried to change the #5 CoP electrical connector. While I had the CoPs out I also broke torque on the spark plugs and re torqued them. They only have about 6000 miles since they were replaced. It took me about 10 hours plus a short break between each cylinder. I set up a board over the radiator and some padding on the board to lay on my belly while doing the work.

I noticed a couple of interesting things. 1. some of the wires in the original harness are 18 or 20 gage, and others are 16 gage. Also the color coding is different for each injector and CoP, so I was very careful to compare the old plug to the new plug in orientation to make sure I didn't reverse the wiring when I spliced in the new connectors. 2. some of my wires in the original harness have a bit of corrosion between the strands. Somewhere down the road I can imagine a wire corroding all the way through from the inside out and giving me headaches troubleshooting the problem. If I remember right it was determined by this forum that nobody makes a new engine harness for this truck.

 

Nice work

 

Now that you have known good COPs installed the next time you change plugs you should only need to change the boots, too. The coils will far outlast the boots.
If you leave the plugs in for more than 50k I would retorque them at 50k.
According to the Ford Wiring Diagrams the COP wiring is all 16 gauge, the fuel injector input lines are 18 gauge and the fuel injector output lines are 20 gauge.
All the COP and fuel injector output lines go to the PCM to be individually controlled so every wire has a unique coloring.
Each wire can be checked for continuity to one of the pins on a PCM connector.
The input power wires for the COPs and fuel injectors are all common sourced so they are RD/LG 16 gauge (COPs) and RD 18 gauge (fuel injectors).

 

I'd like to see a picture of the board you laid on. I am thinking about a plug change and have thought about an easy way to get access.

 

It took me a few hours and $50 in parts to reroute hoses and get access.