i have a gen 2 jdm b16 in my hatch and when i start it after its been sitting, itll sit at about 2500-3000 rpms for a minute or so, then down too 1500 and bounce between 1500-2000.
eventually it calms down to just under 1000.

ive checked my vaccuum hoses for leaks, checked my throttle cable, and ive cleaned out my fit valve.

anyone have any more ideas? does my fit need to be replaced?
thx

 

cold idle start, or whatever its called on the back of the intake manifold its held on by 2 bolts unbolt it and clean my metal screen but do not break it. should fix you're problem

 

Idler sensor? my friends does the same