Hesitating Problem

[TurboAWDKID]

When I start to go foward, the car seems to hesitate once it starts seeing boost. It doesnt rev out like a slipping clutch, nor does it not build boost. It does this in every gear. I noticed it once the weather got really cold, but it seemed to go away after the car warmed up. Now it does it almost all of the time. It feels as if "somoene" is holding the car back, then letting go, then holding it again; almost like applying the brake slightly then letting off continuously. I just had Buschur put in a new motor, turbo, and tranny, so all of the plugs/wires/clutch and such have been replaced already. When I am at full boost, 16psi, the car doest seem to be charging ahead like it used to. Once I hit about 4k it pulls fine though. Boost is steady and so are the rpms, it just doesnt want to get going like it used to, a lot like when climbing a hill but jerky. Any suggestions?

 

[bojanglesracing]

Boost leak test. You could be hitting fuel cut.

 

[TurboAWDKID]

it ran completly fine after the rebuild, it just started doing this and never hit fuel cut before. i did a boost leak test before the rebuild(by buschur) and nothing, but i planned on doing one after i put in my SBR FMIC kit on saturday to make sure things are on tight. it did it again on the way back from class today, but it went away after it was at operating temp for about 10 mins. im pretty sure its not fuel cut, i know what that feels like. thanks for the help. anyone else got any ideas?