What causes oily black soot in the intake runners and throttle body ?
Yich. The car ran fine. Amazing to take things apart and see the grease, dirt, corrosion that didn't seem to matter.
More amazing: To see the tiny needle bearings in the throttle body for the shaft, and all the parts in good shape after 200,000 miles. I'd expect to see worn out cheesy bushings and plastic crumbs from newer disposable cars.