Why is it I publish my story improve my rank when I publish the next episode but after that my rank gets worse?
Maybe because when you first published your story people might be reading it so your rank improved but now only a few people might be looking forward to your story because story ranks depends on the no.of episodes a person reads of your story,if it reads more than one, your rank moves up. 
Moved to Resources section! 
Oh thank you
Closing due to one month of inactivity 