yeah,i guess it would be clearer if i would mention which car!!
Actually, for either of the ones in your profile it's the passenger side firewall.
RKBAD, please edit or delete your post so others happening on the thread won't be confused. (Mod, please do so if RKBAD doesn't check back.)
Dean, the M119 was also known for having ignition wire connector problems, so I'd take a hard look at that, too. I'd probably just swap connector and wire with #3 and see if the misfire moves. If so you know the coils are good.
Plugs are 30K items IIRC for the M119, so if it's been a while pop in some new ones. Nothing fancy, just the regular ones.