Under Extrusion help

[classified 0]

Hello,

 

I am facing an under-extrusion issue and I don't know how to solve it. I've re-leveled the bed, Printed with a higher temp and increasing the flow rate, I even changed the nozzle and bowden tube, and tried different PLA and nothing seems to work. The only thing that works is if I print my part with a high infill of  50% or higher it will turn out perfect. The problem is I want to print big parts and use less material, and I will be happy with printing them at a 10% infill (That's what I've been doing before this problem started), but if I print under a 50% infill the part will not turn out well and won't be solid. How do I fix this?

 

Thanks in advance.