[Scottem]

change the fluid and filter// before doing so, smell the dipstick for a burnt smell and look for black specs. Find any irregular things in the fluid and thats a hint that something serious is going wrong in the trans

check the vacuume module at the trans end of the vac line // most of the time your better off replacing it

check all your vac lines in the engine bay, low vac can cause lazy shifting among other things

never add any fluid additive to an auto trans, does the factory use additives?

good luck ! If issues continue, then consider having a qualified shop look at your trans ! Rep is everything for trans shops, so ask around !