My cousin replaced the coils, plugs and battery on his 90 300zx NA. Has had a misfiring problem for a while now. He claims that his wires are all snug except for one. It doesn't make a difference in the engines problems while running if he unplugs the wire and plugs in back in.
As he describes, it's the plug closest to the headlight on the passenger side. Not sure which cylinder it is because I'm not familiar with the engine itself. I've told him myself to replace the entire wire set and see if that solves the problem, but he wants to know if it could also be linked to any other problems so he can take care of it all together without having to make multiple trips to the parts store.
Would greatly appreciate any feedback to the source of the problem. I think I'm pretty sure. If anyone has any links to videos, or tuts to show how to change his wires by himself that would be a great help too. Thanks guys!