1995 honda civic ex with a jdm d15b swap into it, start the car up and the rpm bounces between 1500 and 1900 at idle, any ideas, the only vaccum line unhooked is the Purge Control solenoid, its located on the back of the intake manifold but my motor doenst have a place on the back to hook that sensor up...

 

does it just do it when it's cold/semi cold? It could be the air valve on the back of the intake not closing all the way or something.

 

where is that at? if ur talkin about the purge solenoid i dont have one it wasnt on the motor, motor was from japan..