I have one cylinder that is not firing I've changed the rotor button. I can pull the spark plug wires off the other plugs and u notice a difference but when u pull the wire I'm having problems with NO difference. This is a 99 accord with 190,000 miles.
Are they any thing else I can check before I go any further.

 

Compression test would be the next thing on my list.

 

V-6 or 4-cyl?
How's the tune-up stuff? Spark plugs, etc?
I'm with shipo on the compression test.

 

compresion test would be my first step , if it comes back with low compresion check ur valve clearances on that cylinder , if there good then u have leakage around the rings ,
if the coprsion tests the same on all 4 cylinders the next step would be to see if u have fuel