Moving too fast from a stop causes RPMs to drop

I am having a problem with my 93 camry. When I am at a full stop (engine at normal op temp) if I press on the gas any more than a tiny bit the RPMs will drop suddenly, and jump back up. The is an automatic, but does not shift at all when this happens. Just as quick as it drops it jumps back up. If I am careful I can avoid it or in a few cases it will happen up to 4 times before the car moves naturally.
Anyone have any ideas as to what to tackle first to determine what is causing this?
Thanks

-=RS=-