Canon MX890 not printing black

Hello,
I have a Canon MX890 that is giving me trouble, and I need help, please. If I print in color (even if it is black//white) it will print blue/purple color for black ink. However, if I print in black, then nothing shows up. I have cleaned the head. It is also showing the new black ink is now empty, right after I replaced it...I need a color printer for my business, and this has me tearing my hair out-almost...any ideas out there? I really need help on this, please, and any ideas are most gratefully accepted. Thank you in advance for your help.