I had exactly the same symptoms in my 1994 Geo Metro which had no hitch, (that 1.0L 3 Cylinder engine could barely pull the weight of the car). I finally got rid of that car rather than deal with the issue.
Dave Coon www.nflcrimes.com
SilverStone Metallic
2003 Baja Sport 4EAT
"Capped" with A.R.E. Topper