Illustrator colors way ugly

I have an epson c84 printer and am using Illustrator 10. My problem is I can’t get the colors to print the way I see them on the screen. I have a specific color, even CMYK/RGB %code that I used in creating the design with a different computer. It was sent to the printers and printed exactly as I wanted. The client now wants me to do additional work using all the same concepts and color schemes. When I use the same %color codes on my computer (different from the original one I designed on) and try to print it out it looks horrible, not even close. I messed around with different color codes and printed them off and just can’t get a match at all. Even changing from photoshop to illustrator everything looks horrid.

Anyone have anything they can hook me up with to get this straightened out? This is very stressful, and a waste of my whole day experimenting with no real results.

Thanks in advance.