Came home this evening and tried cracking the injector lines again, and could not find a cylinder which acted worse than any other.
In the course of all this I have come up with two findings;
One is the engine no longer overheats.
The second is that I don't believe it is a dead cylinder. There is a vibration that you can feel sitting in the drivers seat holding onto the wheel. It is very pronounced. When standing at the engine reving it up, you can hardly tell that there is anything wrong. The reason I have thought that it was a dead cylinder is that the vibration is at engine speed. It's like the torque converter or harmonic balancer are heavily out of balance.
I'm still stumped. Driving down the road is brutal, the vibration is so pronounced that it warbles. If you've ever sat between two airplane engines both at slightly different speeds, that's what I mean by warbling. The vibration goes in and out, in and out.
It is so bad I won't drive the car, or let my daughter drive it. It feels like something is going to tear up.
I've thought motor mount, but even if the engine were welded to the body structure, it shouldn't vibrate this bad.
The harmonic balancer runs smooth visually, is tight and seems to run out perfectly.
I'm totally stumped,
Thanks to everyone