new engine lacks power on take off
 

have a 07 ford f 250 6.0 TD has tuner. installed new engine. starts up great, idles good but has o boost at idle. when taking off barely accelerates, slowly builds boost, takes 4-5 seconds to really take off. once it builds up to about 10 lbs boost then it really starts to move. after that its fine. floor it and it moves. come to a stop and it loses all boost and takes off slow again. put in new turbo charger, ecm, new ficm, icp sensor, egr delete kit, ebt sensor, fuel pressure regulator, map sensor, map hose, air intake hoses, truck was sent to dirty diesel and they could not find the problem. truck was sent to Mc cree ford two weeks and they couldnt find the problem. i`m really getting desparate need help :argh: