LORELAI: No, Jim is coming here to fix the garbage disposal.
RORY: Jim Dunning, got it.
In an earlier episode, Jim Dunning is mentioned as the auto mechanic who used to run the Hewes Brothers garage – before Gypsy became the mechanic there (although there may have been someone named Musky in between them, it’s not made explicit).
Either Jim Dunning (who Lorelai couldn’t remember before, not even whether he was tall and thin or short and stocky) is now fixing garbage disposals, or Rory is joking, as if “Jim Dunning” has become their name for any random guy who fixes stuff.
The Annotated Gilmore Girls 