Sounds like one of the plug wires isn't seated right either on the plug or on the coil.
You stated you didn't remove from the wires from the coil, but were you changing plugs one by one or did you pull all the wires off the plugs at once?
If you pulled all the wires off the plugs you might have 1 wire one the wrong plug.


1996 2.5LT V6 Contour ATX My Tour+help/info pics E0 rims, Gutted Pre-Cats,CTA Custom Exhaust & Intake, Diablo Chip.