what is this...

I have a ZC, on the back of the manifold are 2 hose output stems, the left one is capped and the right one goes to a small black thing on the firewall right to the left of it. Its got wires goin to the whole setup on the bracket. The unit that hose is goin directly to has some sort of cap on it that can be removed ive tried. Point being... my idle goes up and down, more so when i have my foot on the brake. I heard cleaning the ICV which i believe is the unit on the back of the manifold with the 2 hose comming out of the bottom and the plug on the side being held on with 2 bolts. But still nothing, so when i was messin around i disconnected that hose from the manifold to to the black thing and my idle started jumpin up and down alot. So what is it and what else can i try, oh by the way is it ok to spray the whole ICV or should i be careful of the electrical component inside? Thanx for any1s help this has been goin since i put in a chipped pr4 ECU, do you think that ECU is ok to use for the DOHC ZC? Thanx again!

chipped pr4, your timing is gonna be pretty high for that motor, make sure you run super.

surging is usually caused by a vacuum leak so i would check that out, if your sure you dont have a vacuum leak. if the motor has a fitv valve. take the cover off and screw the inside in and that should help

Fast Idle control Valve possibly... not sure if the ZC has one though...

the black container is the Charcoal container, for emmisions, it can be unplugged with no problems.