Hey all,

I recently fixed my ECU, and got my car to pass CA smog, but in order to do it I had to pinch the IAC hose to get the idle down to spec for the smog computer. The engine idles around 900-950 rpm. It is clear that the idle is high due to air going through the IAC path. When IAC test point is grounded idle drops and I can set base idle to 720 rpm with knob on throttle body.

Now I have done all I can think of to figure out this issue, so I have come to you for help:

What I have done:
Cleaned throttle body.
Adjusted throttle and throttle valve switch.
Tested throttle valve switch (#3 at ECU) has low ohms at idle, and other contact (#12) is infinite at idle.
IAC is cleaned, free, and measures OK, and swapped with second one.
When IAC test point is grounded idle drops to 720rpm.
When IAC hose is plugged idle drops.
Temperature sensor is spot on (measured from ECU) with water temp at thermostat.
O2 Sensor readings bounce between .4 & .9 ish Volts on volt meter.
Engine runs about the same when O2 sensor is disconnected.
Engine rpms hunt up and down when AMM is disconnected, but still high.
Timing set at 12 BTDC, but at 950 rpm so I could pass smog. It was at 14 BTDC probably due to high idle.
ECU swapped without any change.

***EDIT***
Took out fuse that feeds AC and the idle is now down to about 800, pretty close, but still a little high.

Known problems:
Engine has a bit over 300k miles, but recently showed good and even compression.
An exhaust stud has broken (one closes to firewall), and manifold is warped a bit probably allowing an exhaust leak.
Water pump has a slow but steady leak.

No matter what I do, engine idles steadily at around 900-950rpm.

****EDIT**
Idle is now at about 800 rpm with the AC fuse removed.
AC is broken, how can I disable the power to the AC system without pulling the fuse?

Any ideas or suggestions as to what could be going on?