are you sure that your ISCV BRAND new, not a fake?
is your TPS adjusted properly?
I have the same problem - sometimes engine revs up to 2000rpm when start. But not depends of engine temperature - this can be when it cold or warm. My TPS is adjusted to 2 degrees when closed. But I found strange phenomenon - if I see from ECU Pectel Monitor that TPS parameter is more then 5 degrees(6 or more) when ignition is on(engine is not started yet) then revs will be 2000rpm when I start it. Revs can drop down to normal 900rpm whithout any activities from my side after some time, but sometimes I need to unplug ISCV, after that revs drops down and engine runs OK and I see that the TPS parameter dropped to 2-3 degrees as it was adjusted. Then I plug ISCV back and its ok. But I dont understand if this is ISCV problem how ISCV can affect to TPS parameter, I mean why TPS degrees(voltage to ECU) drops when the ISCV is unplugged??? Please help to understand.