Iphone move object slower than computer.

i create some game object with transform.Translate script to move . As I test it on computer, it work as what i expected, but when i build and test it on Iphone, the game object is moving slower. And I know that it will be fixed if i use fixedUpdate, but i use Ienumerator function to move the game object and i don't use any update function at all. Could anyone explane me why or how to fix it? I use C#. thanks.