why does my idle go crazy only when i start it

[240sxspeedracer1]

pretty much the title explains it.  
I go to a store and turn off my car.  when i turn it back on while the car is still warmed up, the idle jumps around at around 5k

[camppain]

well ive posted in topics like this one before there is a bulliten out issued by nissan for this (you only know about it if you work for them, it helps u do your job better and isolate certain problems) back to the subject at hand
try a search for idle ive been lazy to scan the bulletin but i will try in the next month or so along with a hud diagnosi write up

[240sxspeedracer1]

trust me, i would have searched and found it and not bothered anyone but...........
this dam search isn't workin.  That SHlT pisses me off.
So please, somebody who had this problem before or knows about it, tell me what it is so i can fix it.
It's quite bothersome.

[91CRXsiR]

my 89 does the opposite of that .. when i cold start it just drops .. all the way till it just dies... then after its warm everythings good but it still idles at 500 RPM...

[240sxspeedracer1]

thats what i meant to say, that it drops down to 500 rpm, not 5k, my bad.
only when the car is wamred up and i turn it off and then turn it back on.

weird shiznig, very weird shlt, it just fvcking pisses me off, u know?

[91CRXsiR]

well i started having this problem only after i took apart my air intake system so it might be linked with a vaccum leak or somthing i dunno...