When installing you new plugs you have to be careful that the area around the spark plug hole is clean. If there is gunk, then you can pick that up when you are trying to line up the plug and if you get enough greasy dirt packed onto around the electrode, it can prevent the plug from firing. Also, if you did not do the plugs one-by-one, you need to make sure that you do not have any wires on the wrong plugs. Lastly, make sure that the plug wire is all the way on, fully pushed over, sort of snapping on the end of the plugs. Hopefully, you didn't damage any wires when you removed them, did you. You can't just grab the wire and pull it. You have to work the boot off of the plug ... BTW, why do you say "a new wire " ? DId you only replace one spark plug wire, or, was this a wire to something else ?