Ive been doing some more looking into this,
If i leave the Idle valve completely disconnected, the car and starts, a little lumpy when really cold, but within 2 minutes its ticking over at 1000rpm with no issues at all.
With the ISCV plugged in the car will increase and decrease its RPM which is caused by the ISCV,, looking at the signal voltage with respect to GND, it sits at 5V when idling at 1300 and then for no reason it will run to 3V ,(increasing duty) this cycle repeats every 10-15 seconds continually.
The base idle screw is in the right place when comparing to other throttle bodies ive seen, the TPS voltage with IGN on and engine off is 0.67V and i have checked there are no bad spots.

Last night , i unplugged the ECU for 5 minutes and reconnected it and started the engine with the ISCV plugged in, it immediately revved and then settled to 1000rpm, sat for nearly 3 minutes, and then began to hunt up and down, arrrgh!!
The CO pot signal voltage is 3.5V, but the AFR with the ISCV off is 15 ish or 1.01 lambda when warm so the fuelling should be right

Its really bugging me now, i just cant figure out why the ECU is always cycling the demand for the ISCV.

I know it needs setting up with the correct chip, but this sort of behaviour is just something very silly that i cant seem to pinpoint.
Any OFAB RST experts out there???
Cheers
Rich