Jumping with Timeline, why doesn't work ??

I’m trying to do this jump that you can hold down the button to increase its power. But it does not work. And I don’t know why. Can anyone explain what is wrong with my logic and how to make it work ? I really need a highly customizable jump, that I can work with some peaks in height and holding button time. I thought of using ‘’ Timer ‘’, but it doesn’t seem like what I’m looking for. Timeline seems the way… And I think that I could make it work somehow. So, please… Lend me a hand.