there are very tricky vacuum lines that run underneath that intake that will cause it to run rough or not run at all but if these are intact and in place then i would by new intake gaskets and make sure you have them right side up and it should tell you on the gasket if not it will not seal correctly and try it again with the correct torque specs and correctly tightening them down , you should not tighten down all one side you need to start in the middle of the intake and switch form each side every two bolts you very well could have warped the intake by not tightening it down right
