The ISCV is only used when cold as there is a richer mixture or when theres a heavy electrical load, unplugging when up to temp will have no effect at all. As said defo sounds like the CTS this controls the base level of fuel injected from the map right from freezing up to boiling. When faulty they cause the problems you describe.

The fact that your revs stay high show the ISCV is working.

Martin