Boost leak in throttle body?

I just put in a new isc motor and its idling perfect. but when i shift from 3rd to fourth or fourth to fifth the rpm's rise to 3,000 and stay there until i shift and let out the clutch. Any ideas on how to fix this?

 

[codeofdastreets]

I always go with a non turbo throttle body and block off the isc module..I even cut off the 3 vaccum ports on top of throttle body and weld them shut..this give you less chances of boost leaks..