Update: the checks suggested above were made, as well as checking charging system output and battery condition. The battery was indeed old and a little low in the cells (none exposed), so we replaced it. Drove home fine; despite heavy dewfall it drove to work fine - 36 miles through Pittsburgh, good mix of city/highway.
Coming home was a nightmare. I set the cruise at 60; all of a sudden on a downshift it started bucking and surging, boost went to full, rpms up to about 3500. I disengaged cruise, cut the fan, the radio, etc. Things settled down but it was still indicating boost when it shouldn't (low load/coasting downhill). Then in stop and go traffic it stalled four or five times. As long as I kept moving it was fine, though occasionally bucking a little, and engine management seemed off - rpms were too high, boots indications, it just wasn't running right. Near home is a short, steep climb. I got it rolling good and wound it out. Got it over the top, and coasted down the other side, seemed ok - then on the 2 mile level stretch home thought I was going to leave parts on the road. All kinds of clunking and banging, the engine was laboring to go 30 mph, boost to 75%, and I thought from where the sounds coming from that either my rear differential was going to pieces or I was loosing the u-joints on the driveshaft - Until I thought, "Hey, Ickabod, this thing is front wheel drive!" There was a distinct smell of some kind of hot gear lube or hydraulic fluid.
After dinner, started it up, shifted through the gears and checked the tranny fluid. It was full, still quite hot, and it smelled "fumy" - not burnt, but giving off fumes. Checked alternator output, a little over 14 volts. Idling smooth. Engine oil just fine, recently changed. Ran it up to 4000 rpm , sounded great up to 4K, at which point it coughed - did this a couple of times. Ok, it probably needs a set of plugs and wires, and the ignition modules are original too, I believe. Put it in drive and ran it up to 3000 rpm against the brakes. Again, sounded good, no boost indicated.
So what the heck? A confluence of engine controls and possibly a tranny issue with the lock-up torque converter? Wifey wants it gone, so...
Thanks all!
