When you run the INIT Fill, But it will be for all the colors, not just one position. There is no way around this using this function. This function creates a vacuum/suction of the head to help clear any air of the system and will help assist in clearing stubborn clogs. This means you will be using ink in all the other positions. You will have to possibly run 2-3 initial fills for this printer model, they are not equivalent to the INIT FILLS run on the older printer models 7880/9880, when one was more then enough. Also, if you successfully clear the Cyan channel, you will then have to introduce the pigment ink back into the system using the same procedure. Once again, using more pigment inks in the other positions.
Hope this helps-Kindly, Kelly