* The injection pump WAS damaged.
There where at least two major delivery valve issues found, now repaired and calibrated.

My advice when we spoke on the phone when he picked it up from the injection shop was:

* Install the injection pump and see if the issue is gone, before any further diagnosis or repair.

Until he reports back with some results, there is IMO no logic putting more time, labor, and/or money forward.

********************************************

Reviewing:

The engine was rebuilt at 40k miles:
* #2 cylinder issue has been there since then, and may have been there to some degree before.

The #14 Cylinder head was replaced with a #20:
* #2 cylinder issue was there before and after.

* The engine consumes no lubricating oil or coolant.
* Coolant system is not showing indication of combustion pressure.
* The engine started smooth when cold.
* The engine ran progressively worse as it warmed up to full operating temperature.

Engine running; His mechanic "cracked" the injector lines loose one at a time.
* Only 3 cylinders where significantly affected during this test.
* The other 3 made NO difference.

.