Jeff - thanks for the reply - this is probably why my Volvos drip from their plugs, too, but I just chalked that up to mileage (should crack 200k in my '89 740GL sedan in the next few weeks - very excited!).
Anybody know if I can simply get another copper washer from just anywhere - hardware store, auto store, etc. - or do I need a special washer that compresses when tightened to make the seal work, and/or fits the seat exactly?
Thanks also for the reply on the low idle - I'll take it to a local Indy shop, and let them plug in their computers. All I'm armed with is a multimeter....