That's indeed "true" black.
CMYK 0 0 0 100
But it seems what you want is deep black or color [registration mark]
CMYK 100 100 100 100
Is this design for print or screen?
If for print, you might want to get some information on printing processes.
In the Illustrator preferences there is a section called Appearance of Black.
You may take a look at that and change the settings there.
Thnak you! this was the fix!
As Kurt is suggesting, in Preferences > Appearance of Black, your On Scrren choice should be "Display All Blacks as Rich Black." In the dialog window, you'll see the difference between 100% K and Rich Black.
On the other hand, if you are looking for a Black that PRINTS darker, you need to set up your own Rich Black Swatch in the Swatches panel. I usually use: C: 50% M: 40% Y: 40% K: 100. You may want to discuss creating a Rich Black with your printer to see what they suggest. This darker 4-color black can be especially useful in creating Gradients with dark colors. Using 100% K could look very wimply and grayish instead of dark black.