Finish print with week structure

Hi to all,I had problem my nozzel was dirty and print was very bad and structure was week ,i clean nozzle with soaking in aceton and with needles that i get with zortrax and prints start to be ok but on the and on print  usualy again start to print like week structure like there is not enough filament extrude,Chek out images znd you willl see..What can be problem?Best

Hey there milostutus.

Did you try cleaning the hotend?

HI.I Will try with that as well.Do you think that can help?