Mis-Fire

Allright guys and girls, I've got a '97 4-dr, 2.2L Cavy with a "92 2.2L Corsica motor in it. I put it in last June, worked fine, until now.
I'm thinking it's the coil pack, but I'm not a hundred percent sure, so here's the deal...
My number 3 cyclinder is not firing BUT, I have spark coming through the all the wires (including cylinder 3), I checked with a tester. But the spark is not passing through the plug. So obviously I changed the plug last night in the Crappy Tire parking lot, same thing. I got home and checked for fire again, and exact same thing, so I just unplugged the injector so I don't screw my motor.
Would this be from a weak module on the coil pack? And I thought that if the coil pack was bad, going or gone it would have 2 dead cylinders instaed of just one? So should I change the pack, or is it something easy that I'm over looking?

Thanks

so you have a tester which you put inline and it shows spark but you have none you say ........mmmmmmmm weird .how are the plug wires ?