I came across about 75 American Bosch 2 hole injectors for our Multifuel engines, took them and 4 injector pumps and a screwed up injector pop tester (courtesy of one of our members) to DW Diesel Electric in Latham, NY last summer. They tested all the injectors and put about 15 in a "GOOD" box and the rest in the "NOT GOOD" box, built one perfect injector pump out of 4 parts pumps(and set it for 5% more power than stock), and fixed the pop tester. It all cost me $475. I know they charged $295 for the pump rebuild, so $180 went to fixing the pop tester and testing all the injectors. I was satisfied with the cost. They showed me two types of injectors, 1 being an adjustable by wrench to increase pop off pressure injector, type 2 being adjusted by shimming to raise pop off pressure. They can't get the new shims anymore, so they said to save the bad injectors for parts for the future. My 2 penny's worth. JT out