I'm hoping some one can point me in the right direction for the possible culprit.

Background: My car started to lose power when on the highway, and stalls when getting off.
After a lot of tracing and guessing, I've replaced the TPS, Bellows, all rubber hoses associated with the air intake and replaced the MAF. I also repaired/modified the check valve and assembly associated with the air pump.

I set the idle in accordance to: http://www.jagweb.com/aj6eng/fault_codes.php
Part: IDLE STEPPER MOTOR SETTING PROCEDURE for 3.6 engine.

I was able to set the idle with the idle control valve connector off to 550 - 600 RPM. When I reconnect the connector, let it idle for a minute or two, and restart the car, I get an idle of 1100 RPM. She just won't take the setting.

Any helpful hints would be greatly appreciated