I had the exact same problem last week. Our printer told me to make sure that every piece was saved as CMYK before it was placed into InDesign. This helped some, but then I tweaked the colors up a lot before printing.
Thank you for your reply. I know there are difference between computer screen and print but this looked pretty drastic. After some research I got somewhat better results. This may help someone.
"I have had this issue as well -- and eventually realized that what one sees on screen and what actually prints are two different worlds. Basically, as far as I can tell, computer monitors are calibrated RGB output -- therefore, when you are looking at a CMYK artwork, the blacks (100% K) are going to look kinda greyish, because it's not a RGB black. Illustrator cheats this somehow, so the CMYK blacks look truly black when working with files in it.
Something I always do is check the PDF settings when saving your file as a PDF. In the "output" tab, be mindful of the color conversion setting. If it's set to "convert to destination" and the destination is an RGB, than your PDF will look normal on screen, but may not necessarily print correctly. If you convert to a CMYK destination, it will probably look wierd (as you are describing) on screen but should print just fine... it's all experimentation and understanding the two color modes.
Hope this helps."
colors are somewhat faded but not as bad when I convert to destination CMYK