does it drive ok when warm, what the fuel consumption like?

have you checked the FPR, has this played with at any stage? is the vaccum pipe to this ok?

also once engine is warm and upto running temperature try unpluging the Idle Control Valve - does the engine die after this or keep running at the correct rpm (it should run perfectly when disconnected when engine is warm)

also what setup is the car?

And finally check all wiring you have have a break down in the loom somewhere and the ECU isn't ready the sensor values