Can anyone tell me how can I solve this ?
It’s happens to all layers, even infill (it is colapsing because of this), but the outer walls are perfect. I’m using Simplify 3D and I have a heavy modified Prusa I3 clone turned into a cube printer, that I’ve been using it for over half a year. But it never happened to me. I checked everything exept the extruder.

See the “baconing” pattern? That indicates over extrusion. Also see the overall pattern/banding across the top?
To me that could indicate a mechanical issue.