have you got a bleed valve mate?
thats the easiest way to set it up rather than keep adjusting the actuator.
simply fit one inline if you havent got one,between turbo and actuator(on your fuel hose you used.)
id set it at about 12 psi and see if it drives ok,take it easy as your fueling needs to be matched to your boost etc and if it feels like its holding back then back off the boost.
if it drives ok then tweak it a bit till your happy.
i run 18psi on mfi with no probs mate
but if your unsure what your doing,then run something like 8 or 10 psi till you can get somebody to set it up