Sounds like maybe either your spark plug wires are not in the proper order on
the cap or you may have inadvertantly pulled another plug loose while you
were working on the tune-up.
The way I remember the spark plug wire order on the distributor cap is to
think of the four towers on the cap as pointing to the cylinders that they go
to.  Now just cross the pair of wires on the passenger side (US) and you have
the wires in the proper order.  In other words the two wires on the driver's
side go straight from the cap to the plugs, but the two on the passenger side
cross over each other and go to the opposite plug.
If this is right then check the connection on the coil itself (can sometimes
get pulled loose) and the hall sender plug on the distributor.  
Hope this helps.

Thanks,
Ken Wilford
Van-Again
John 3:16
http://www.vanagain.com
Office: (856)-765-1583
Fax: (856)-327-2242