i just swapped my eg with a gsr the engine was already in the car but i pulled it out to paint the bay and polish the engine and replace the manifold to a skunk 2 it worked fine before never gave me any problems now it woint rev all the way someone help

 

Look at the check engine lights its telling you, and fix those.

 

http://phearable.net/tech/mil/readcodes.html
http://phearable.net/tech/mil/troublecodes.html

 

you got solid CEL, right?
ECU problem try to use good ECU first.