I don't know how much you know about diesels so don't be offended. if you loosen the inlet fitting on the injector pump, can you pump unbubbly fuel out with the primmer pump? And are you sure you don't have air in the lines from the injector pump to the injectors? You can get the air out of the injector lines by loosening the fitting at the injector and turning over the engine. It makes a little mess but you can contain much of the fuel with shop rags.