well i changed the power valve out from the 6.5 to the 2.5 and i also installed the weakest spring for the secondaries.
I read through the piece of paper supplied with the springs about if the engine bogs or has a flat spot and seem that the engine has a slight bog but the hesitation has improved. the original spring was black (heaviest). I installed the next stiffer spring up from the weakest one and will test the car tomorrow.