Here's a couple of suggestions that may help you.

First ... sing what it is you are trying to play. It doesn't matter what syllables you use, or what it actually sounds like coming from your mouth, but the important thing is that you have the thoughts INTERNALIZED before you try and play them. By this I mean that if you can't SAY what you are trying to play ... you won't be able to play it. You need to understand it in your mind first before you can train your muscles to respond. It is your brain that tells your muscles what to do anyway!

Secondly, try writing it out. Having a visual picture can really help with working out the coordination issues. Seeing the figures notated AND being able to sing or say the rhythms (like I mentioned earlier) will probably get you over the hump. You'll be playing them in no time at all.

As you know, what you are attempting is nothing more than math. Clap out the rhythms while tapping your foot on the pulse of the 4/4 time ... which would be quarter notes.

Let me know how it works out!