have you followed the setup procedure for idle in somewhere like the haynes manual?
I've had to do mine a few times to get it right but its ok now.
without the iscv the idle should be alot lower than 1200, in fact in some cases it will be almost too low but the car should just run @ 600/700rpm.
once you plug the iscv back in the idle should fluctuate a bit then re-learn and settle at approx 900/1000rpm.

there is a set procedure to re-learn/reset the idle and it does help alot with the car idling form cold/hot and regaining idle when pulling up to junctions etc.