94 corolla transmission trbl?

Runs good while in in neutral. Acts like timing is all messed up if put in any drive position (automatic) Most people I spoke to say the transmission's gone bad. I had an old Civic awhile back, and while it ran perfect in neutral any load would throw of the timing (timing advance valve was not operating properly). I guess my question is could anything other than transmission be causing my Corolla to act this strange? Thank you everyone in advance for any advice