The problem is usually found in the harness itself right near the plug on the injector. The copper breaks inside the insulation and testing it in most cases will test good because of some continuity in the strands of wire that remain intact. You have to hook up a meter then wiggle the harness near the injector and give it a tug too while watching for fluctuations in the meter to find it. It's usually within an inch of the plug that they break inside the insulation
