Canon IPF8400 - Precision problem

Hi!
It's been two years now that i'm working with an IPF8400 and this printer is giving me dreaming result.

But recently I have an issue about precision for a client that have picture with big black mass and I have to reduce the total ink for better result but it produce horizontal line in the picture like each pass of the printer's head are a little off. (1mm maybe).

The paper that the client ask me to use is a thick one (Canson infinity platinium 310gsm) and in the ICC profil of this printer, it have one for 240gsm and after that it's "thick photo paper". So I set the paper at "thick photo paper" with the Canson's color profil from the site web.

The photoshop file is set in CMYK coated with an limit of total ink of 280%.
I tried to adjust manually the alimentation priority but it didn't fix all the problem.

And by now, i'm out ressources since I didn't had a special training for that kind of work. I learn fast but it seems to not be enough sometime...

Thank you for your time!

 

You might want to try setting vacuum to strong in printer profile.

 

thank you for your advice!

I'm making more research it seems to not be only that, I find out that I have to replace a printer's head. It might fix a lot of things!
I tried to adjust the the height of the head and it gave some result but i'm worried about the nozzle. If the paper is thick, is it gonna damage it?

 

It's shouldn't as long as you have the GSM set correctly on the printer. The head adjusts by itself.