Blacktop 20V high idle

[jdm86gtz]

The ISCV is fully electric and controlled by the ecu on the 20v.
When it's idling at 2000 at normal operating temperature plug the inlet pipe to the ISCV and see if that drops the idle back to about 850rpm. If it does then the valve is probably gummed up and could do with being cleaned out with carb cleaner etc.
If it doesn't you will have to look for other vacuum leaks.
Also check the vacuum actuator under the throttle bodies that catches the throttle linkage and slows down the final closing phase when you release the pedal.
Also if you can see the throttle blades make sure all 4 are closing together as they are split 2 +2 by the linkage setup.