When i come into boost after 3200rpm.. it splutters and doesnt wanna go! but if i take the revs up slowly not hard boost its fine...

But if come in to light boost, its ok and general driving is fine! No missing whatso ever. Ive turned boost down to 10psi now.. just to check, and its driving fine untill i come into boost ....

Whats the problem? or whats to check first! Im gonna check the car over for leeds, pipes ect... that coulda come off.. just want anyone with experience of this problem to help me

Any help would be appreciated!