Hi i have a problem what im fightin from some time, i already try a couple of things.

1) Increasing extruder stepper curent
2) Decreasing retraction and detraction speed
3) Increasing extruder spring tension
4) Replace nozzle and silicone tubbing

not nothing seam to help
im using SlicerPe, i attahed my current settings, screens, stl and gcode in zip file
problem.zip

I record also how my extruder works
[youtu.be]

This is a picture of issue




Edited 2 time(s). Last edit at 04/18/2018 06:00PM by porlock.

This looks like its happening at a seam location? Perhaps your stringing out some extrusion just before it resumes at the seam leaving the nozzle less than full.
That can happen with PETG often enough, less likely with PLA unless your temp is high.

if you have your temp as low as possible while still being able to print, then increase your non print move speed a bit.
increase your retraction and detraction speed leave the retraction distance low, 1-2mm likely is good
reload a little more filament when detracting to compensate for what was lost during the non print move. There should be a setting in your slicer for this.

Also make sure you are printing internal then external on the perimeters.
I had mine reversed at one time and showed the same thing.