When I pulled the cap off of the fuel rail bleeder I got bubbles in the fuel.

What is your question?

Why is it when I pull the cap off of the fuel rail bleeder I get bubbles in the fuel. I tightened the bleeder and let some fuel pressure off and it ran pretty good. But the next morning it was running rough again. Done the same thing and it smoothed out. It had a little hesitataion. When running rough it has black smoke.