I bought a rebuilt injection pump from the dealership. Is labeled 11-28-18. The timing is perfect and it's getting good fuel with new filter. Problem is that it idles rough between 1100 and 1400 up and down constantly changing. If I idle it to about 1500 it smoothes out some but not perfect. Max rpm is 2600 no load. Even at max rpm when using it you can tell it's not keeping up like it should. All of the injectors are working and all cylinders are the same temperature. I have been very thourou I think. Did I miss something? What do you think?