how are you adjusting the idle?
I adjusted the idle speed with these steps:
1- With engine off, disconnect IAC connector/harness.
2- Turn engine on
3- Adjust idle speed/screw to the minimum possible without engine stalling.
4- Once adjusted, turn off the engine.
5- Disconnect Negative battery cable.
6- Turn on the headlights and press of brake pedal and wait 5-10 mins while doing this. (obviously lights will not turn on but supposedly this should discharge the remaining energy from the ECU capacitors, etc).
7- Reconnect IAC connector/harness and Negative battery cable.
8- Turn engine on and test all your accessories (wipers, lights, fog lights, AC, radio, turn steering wheel end-to-end both sides). You should have a steady idle now.
First time I ever did this my idle was around 1,000 and looks like I was able now to adjust idle between 800 and 900 rpms