at idle my cars idle gos up then down its a 93 civic ex with a b18b non vtec

 

Usually it's air in your coolant or a vacuum leak.

 

I had this problem with my LS when I went all motor, for me it was the tps was not sitting right at idle. Make sure you adjust the throttle using the throttle cable and it should sit at .49 volts at idle. After you check that, go after the IACV take it off and clean it out really good. Then look for vacuum leaks.