I had a similar problem with my old mazda The reason was belt but not timing belt Another belt wasn't there any more but can't remember which one I will post if I remember
Sounds like the crank pulley rubber dampened area has split and is slipping. I've got one piece all-metal direct bolt on ones from the 91-92's Legends available for $75 shipped to your door if that is the problem.i don't know where that is. What did you mean by the crank pulley splitting??