Big horizontal banding SP540V

Hey all, So I have this issue with large prints where I get some serious large "banding"? Seems to be extremely noticeable when doing large print with a lot of ink. i have searched for fixes to "horizontal banding" but all threads discuss banding causes by feed calibration issues (which i have issues with as well). But this is something different, and through research it seems to be caused by "ink starvation" where the dampers are not filling up with ink essentially. My test prints are fine, however I have to always do a medium cleaning to either show the cyan (contaminated with black) and to clean the yellow from a little bit of magenta contamination. After a medium cleaning it does a fine test print. If anyone can shine some light on this issue please let me know. I have attached a picture as this will do a lot more justice than trying to explain my issue.

 

thanks for the reply! I'll definitely look into those when I have some free time.
We do have the larger dampers.
I don't want to go to unidirectional however, its going to be a big time waster. Even if nothing works.
I never knew we could set auto clean for a set length, another thing I have to check out!
I do believe my troubles are coming from damper/ as well as heater and feed calibration. For some reason my feed calibration looks different that everyone else's. However the rectangle/square line up fine. Thanks again for all the useful tips!