So I recently purchased a 95 GTS. Drove it about 250 miles home and it ran find for about the first 200 miles. Started having a little misfire at crusing rpm. replaced the plugs and wires and the misfire is gone, but now it has an idle surge. Can't figure out what in the world is causing the surge. Any ideas? Car still runs like a scalded ape above idle but its just kind of rough at idle rpm.