Another possibility is lean mixture as this can be a cause of the symptoms that you describe.

You have not mentioned what induction you are using & it is not clear if it still has the turbo fitted or not.
If a stock carb is now fitted then it has a window in the float bowl & you can check the float level just by looking at it.

If all else fails then ensure that the float level is correct, the needle & seat or fuel lines are not partially blocked [including the filter] & that the jets are adequate for the engines needs.