Change out those o rings
Its an easy job as long as you have two sets of wrenches (one of which should be a flare/line wrench set) make sure to hold the line with one while you break the injectors loose with the other or you'll run the risk of twisting the end off of the injector line. Also, don't reuse the injector seals, replace them! the O-rings and seal/rubberholders get old and create vacuum leaks.
Just my 2 cents