OK guys, A buddy and I just purchased an 01 xj with a blown motor. He wants the donor jeep after I pull a few things off it. It has an after market billet aluminum fuel rail and Bosch 4 hole injectors. I have no idea how long ago they were installed. I've already pulled them off and they look good . However, is there a way to test them before I install them on mine? They physically look good and all the o-rings look good. Or do I just hit them with some carb cleaner and go for it? Also, is the fuel rail really an upgrade, or just eye candy?