Inconsistent infill

I'm having a problem with the infill and top layer in my 3d prints. I did a test with 95% infill rectilinear, and the infill is inconsistent.

Instead of appearing gaps with a certain pattern, it seems that some parts get thinner than others.

The steps of the extruder are not 100% configured, as I could not because of these faults. Since this inconsistency also appears with the infill in 100% in some parts of the piece.

Here is a picture with the infill at 45 degrees:

Picture 1

I also tested the infill lines along the X and Y axes, respectively:

Picture 2
Picture 3

My hotend is an E3D v6.

Does anyone have any idea what the problem might be?

you need to configure your e-steps I think.

This appears to be an under extrusion issue. Not enough filament is being fed and this is what the e-Steps is all about.