My '80 300D suddenly started having problems. I was on the freeway heading up a hill at ~60 mph when RPMs started declining. It got to the point where I could drive about 25 mph max. The car idles fine, and accelerates great from 0-25, but after that it starts having power loss, partciularly on any grade. On a significant grade the car will slowly grind to a halt. If I stop for a minute or two on the hill it will start out strong again but then quickly lose power.
Note that I had the oil changed right before this happened, so I'm considering that they could have screwed something up, but I can't see anything obvious that could have caused this.
My initial thought (and hope) is a clogged fuel filter. I'll trying to find a replacement today. Any other thoughts?
Rip