Small holes in perimeter of ABS prints

Hi there,

I’ve been having a problem which I’m not sure if I identify correctly.
I’m printing eSUN ABS at 240/90 enclosed, but in almost every print, the surface of the part has small holes (or gaps, if you will).
I found this: http://reprap.org/wiki/Print_Troubleshooting_Pictorial_Guide#Material_Contamination, but not too sure it that is the exact problem.

Does anyone know what causes this issue?

Thanks! :slight_smile: