Can a fuel injector really sound like rod knock?
My S13 redtop has a clicking/tapping sound coming from the upper area of the engine. The sound varies in loudness and isn't really based on how hard the engine has been running. I can drive it easy in the city and it could be really loud, or it might be relatively quiet after cruising at a constant 3,000 RPM. When I touch the #2 fuel injector I can almost feel where the sound is coming from. The other injectors don't do it as much. The sound goes right with the RPM; as the engine accelerates, the sound speeds up accordingly. Could the problem really be a bad fuel injector and not something more serious like rod knock or a bad head?