Hi. I just bought some BOSCH solenoids to install on some of my fuel injectors that have high ohm readings. The other one I purchased before had the top of the solenoid already assembled, these aren't and have a threaded hole in the top that you see before installing a included wire separator top. It seems like I would remove a screw out of the one I'm removing. Any ideas or approach? I would like to get it going soon. Maybe the screw has to do with some sort of adjustments. Thanks, Herb