Well, then start by checking the grommet on the trottle linkage. IIRC, that has an AOD behind it and those are known to act funny if that grommet is missing/broken. If it's missing, then don't drive it until you replace the grommet or you will be buying a new AOD shortly.
If all looks well there, then check the fluid. Is it low? Too full? Does it smell burnt or look darker than normal (not a bright red color)? If so then all you may need is a trans. fluid and filter change.
These are highly engineered precision vehicles, the first step in diagnosing the problem is to strike the suspected offending part sharply and repeatedly with a blunt object, then re-test.