running on jdm gsr on an EK, my idling wud drop 2 normal then go up 2 about 1500rpm, then go back down to normal idling after about 5secs,
this would happen everytime i shift 2 neutral to slow down then stop
thanx

 

that sounds like a vac leak

check your hoses for leaks

 

and you shouldn't be shifting to neutral to stop.

at least not when slowing down

 

my buddy had a problem with it in his civic SI.... he bruoght it in and all it was was some idle meter thing that had to be adjusted.... real cheap to fix....... and yea downshift to slow down.... save those brakes

 

or I believe even having air in your coolant system can make the idle surge like what your saying.

Easy to find out, just bleed the air out of your rad. 10 min way to start finding out what it isn't, so you can narrow it down to see what it IS.

 

well it could be a vaccum leak, like your tb gaskets or intake manifold gasket, listen to a hissing sound areond your intake manifold, or your isc is bad, thats the device that keeps yuour idle intact, when these things go bad, the idle goes up and down constantly.

 

it's not called an isc like ITSME4G63 said

it's an IACV (Idle Air Control Valve)

 

i think my iac is alright, i cleaned so many times too, i dont see any disconnected hoses. for wat i can see neways.
also my idle speed is around 900rpm. i readjusted it down, but it always goes up there,
o yeah, i
ment when im on a stop i put it on neutral,

 

i change out my fast idle.....works fine after that

 

IACV is for idle when your car is cold

FITV is for when you car is warm.

so if this is happening to you after your driving and the car is warm. i'd suggest the FITV