anyone got any ideas on y my newly swapped engine would be idling like this it idles at around 1500 rpms to warm up but it is constantly jumping up and down about 200 rpms while it idles im thinking it might have something to do with my apexi turbo i just installed but dont know neways im putting on my vafc to try and c if that fixes it will it?

 

i have no clue but alot of honda's i have seen over the years sittin at a light there idle goes up and down. always wondered wtf the deal was. liek vroom then dies then vroom then dies. idk if they purposely do it or if its sumthing that u happens when u hype ur civic up.