This link should help:

https://www.askmehelpdesk.com/cars-t...ml#post2028083

The spark plugs are black when I take them out not carbon its like oil

Check for spark in cylinders 5 and 8. Go over the entire secondary ignition system. Replace those items that really need replacing. Ensure the spark plug wires are not shorting out. It shouldn't be too hard to identify the real culprit.

Everything is new

What plugs are you using?

Check the positioning of the coil-on-plugs for cylinders 5 and 8--ensure they solidly contact the plugs. If no joy, replace the COPs.