'98 B18C1 doesn't have an FITV. It would have been bolted to the underside of the throttle body (if it was '94-'95).

You can clean the IACV with carb cleaner, also make sure there's no air in your cooling system. Clean the TB bore & make sure the throttle closes completely. (Throttle cable sticking?)

Adjust your base idle...
1) Warm up the engine completely, turn off all accessory loads.
2) Unplug the electrical connector for the IACV, probably need to use the throttle to keep it from stalling.
3) Adjust the idle screw (above TB bore) for about 450 or 500 rpm.
4) Plug IACV back in. Reset ECU. Start engine & let it idle (10 minultes??) without touching the throttle.