My friend has a 90 accord that is misfiring on the #2 cylinder. You can unhook the plug wire and nothing changes in the running of the car. Also if you stick the end of that plug wire to metal it sparks. I have changed the injectors around and nothing different. Im leaning toward the ecu but not sure. Any ideas??

 

Have you done a compression test on that cylinder?
Checked the spark plug wire for damage/resistance? Installed it may be grounding out before it reaches the plug, check the distributor cap/rotor for excessive wear/corrosion as well.

 

like mike said do a compression test and if it's bad do a leakdown test to see where the issue is

could be intake valve, exhaust valve, blown cylinder