Well, I installed the rebuilt injection pump from Pacific Injection Service. It helped, but the vibration was still bad enough to shake the screws out of the rear door. I contacted Mike at Metric Motors, the place that remanufactured my engine, and asked his advice. He said to send him my injectors and that they would go over them, identify any problems they might have, correct those problems and then send them back to me.
Metric did find small leaks and evidence of contamination in two of the five injectors. They sent me replacements for those two injectors. Last evening I got the injectors back in with all new round seals in each prechamber.
The problem seems to have been related to the injector issues as it is much better now. I had changed the big fuel filter just before all this trouble started last fall. I think contamination must have gotten into the fuel system when I changed that filter and that that led to all the subsequent problems.
I still have to adjust the idle and perhaps mess with the rack damper bolt a little, but the car ran smoothly last night and I think I finally have what for a long time seemed an intractable problem solved.
Paul Fretheim