Bad filament spool winding

Well, being that it "fixed" it's self you may have had a patch of thicker filament or the line was tangled just enough to cause problems but not stop the feed completely. Are you using Z-Materials?

Well, being that it "fixed" it's self you may have had a patch of thicker filament or the line was tangled just enough to cause problems but not stop the feed completely. Are you using Z-Materials?

Yes, only Z materials and this was using Z-ABS (apologies, should have stated that in original post).