Firstly do you have 2WD management, i.e. L1/L6, by your TPS reading I am guessing you don't and therefore have L8?

Get it up to temperature and disconnect the valve, make sure no electrical load is applied and the fans are not running!

Then UNSCREW the idle screw to increase the idle speed (You will need to loosen a locknut first) it's important this is tightened correctly afterwards, else it and the idle screw can fall out!

You want to see around 850 RPM, reconnect the valve, the revs should raise then fall again.

It sounds like at the moment you are using the ISCV to control the idle speed

Martin