Ultimaker 3 Extended prints pores in walls We have a fairly new Ultimaker 3 Extended.

When printing ABS with the AA0.8 nozzle and the recommended settings (up-to-date CURA) we receive a very poor wall quality that exposes some kind of pores. I've attached an image of those pores.

I assume those pores are dragged by the nozzle when it moves inwards to print the infill.

I already tried to increase the wall thickness or increase the layer height to 0.3&nbsp;mm. Are there other settings I might be able to tweak to eliminate those pores?
While no expert, I'm wondering if you're going the wrong way with tweaking your parameters. 

If I'm reading your question correct, you have a fairly large nozzle (it's a 0.8&nbsp;mm?) and then you're using ABS which requires more heat (230&nbsp;°C nozzle temp) than say PLA does (typically 190&nbsp;°C). Along with that you are using a fairly thick print layer of 0.3&nbsp;mm, where I've normally only used a 0.1&nbsp;mm layer height. You add all this stuff up and it seems to me the nozzle temps are probably not keeping up with the amount of filament you are trying to extrude, and due to these things, you're seeing the gaps in the print. 

My thinking on this to fix your issue is to do a couple of things. You can slow down your print speed to allow the heating element to keep up. Secondly, use a smaller layer height. Both of these things should help, but will increase print times dramatically. You could also go to a smaller print orifice. Lowering the orifice size to 0.4&nbsp;mm would again, increase print time, but would mean less filament extrusion and the chance for the nozzle temps to keep up with extrusion needs.