sounds to me like your throttle body could use a little cleaning or your throttle cable is a tad too tight.
Remove it and scrub it down with an old rag/toothbrush and a nice can of carb cleaner. Making sure to pay extra attention to where the butterfly plate comes in contact with the surrounding metal... it's probably just gummed itself up over the years.
And when you're re-installing it, do not put extra tension on the throttle cable... it doesn't need to be
tight like a banjo string - just snug enough so your throttle pedal doesn't have any extra play.

- an easy problem to fix bro
-jonathan