How to export a PDF as black

I've been trying to read several threads understanding this without success. It's like a pandoras box and I can't wrap my head around it.

I have somehow not come across this problem before, I hardly believe that I haven't noticed this before. I am working on an illustrator document and I am trying to export it as a PDF. My blacks along other colours are exported completely differently. 

I've made my blacks in illustrator to appear accurately and checked different colour settings in illustrator. When I have illustrator emulated it appear as black in illustrator and using the digital colour picker, it too is complete black. If I then export it as a PDF, it appears as RGB 35,35,35, so very grayed out. If I change the colour setting to another one, it appears as gray on the screen in illustrator, but the colour picker says that it is all black. 

I simply do not know what to do. I get the same result both in preview on my mac as well as in acrobat reader. I get the same result exporting it as a JPEG and a PDF.

I don't know what to do. Please help