2004 Thunderbird computer not functioning

I thought I had it all in the original question but here goes again.

I bought the '04 Thunderbird new and had it "tuned" at the 100,000mile service. New plugs, etc. 70 miles later the car went into limp mode. All COPs replaced but diagnostic showed all COPs non functioning. Computer module sent to Ford and it tested ok, put back in the car, more tinkering and now only cylinder #3 is not firing and they are stuck. All believe it is electrical. Some have suggested replacing the wiring harness but there are none available in the US. Others have suggested an old time mechanic to find the electrical glitch and the Ford dealer has said he will not charge for the work done if the car doesn't run. They have checked, or say they have, for corroded parts and injection ports. They are receptive to any suggestions and not afraid to ask for help. I am prepared to take the car to one of the old time mechanics with whom I have spoken who claims to be anxious to look into the mystery since it is what he loves about repairs the most. What do you think?

Just spoke with Ford. They sent the wiring harness to Ford at Ford's request and it is being tested and/or repaired and will be back tomorrow. Ford Corporate seems sure the problem is in the harness so we'll see how that works out.

I guess I don't understand the "glitch" and the cut off. The point is that #3 isn't firing and they have looked into everything mechanical(they say) so electronics are all they are left with. And they have replaced all the plugs, COPs, tested the computer module and suspect the wiring harness which they have sent to Ford and hope to have installed tomorrow(maybe that is the ticket, who knows?). In any event, 7 of the 8 cylinders are firing and they can't find why #3 is not. Just wondered if you have ever heard of something like this.

Thanks, I'll pass the info on to those working on the car. I have had a number of people tell me that things like corrosion, specks of contamination, spark problems, injection problems and the like. I'll let you know what the guys on the ground finally come up with.