Answers to your questions...

You may not need to set the base idle after replacing the IAC. I didn't. I *did* end up doing the steps on page 9 of the Intro and Master Troubleshooting section of the FSM:

2) After completion of the work steps (when the battery's negative[-] terminal is connected), warm up the engine and allow it to idle for approximately five minutes (lights off, transmission in neutral or park, steering wheel centered), then check for satisfactory idle. For 3.0L engine models, if the engine rpm is high, switch OFF the ignition switch, and then, after switching it ON again, let the engine idle for 2 or 3 minutes. This will cause the engine rpm to decrease about 100 rpm, so repeat this procedure until the prescribed idling speed is reached.

If you need to set the base idle speed, here's the procedure from page 14-63 of the FSM.

Same preconditions as noted above...

1) Connect tachometer
2) Disconnect the female connector for waterproof from the connector for ignition timing adjustment.
3) Using a lead wire with alligator clips, ground the terminal for adjustment of the ignition timing.
4) Using a lead wire with alligator clips ground the No. 10 terminal of the self-diagnosis connector (behind the glove box)
5) Start the engine and run at idle.
6) if idle speed is not 700+-50 rpm, use the speed adjustment screw to adjust the rpm accordingly.
7) Shut off the engine, disconnect grounds, plug up the connector again. Start engine, let it idle for 5 minutes, verify that idle is OK.

NOTE that the order of this is slightly different from what you posted, plus you need to ground the No. 10 terminal of the self-diagnosis connector. If you're not sure which one it is, go to MontyMcV's website, download the appropriate FSM, and look in the MPI section for these same instructions plus pictures! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Lastly, I believe the connector you show is in fact the ignition timing adjustment connector.

Let us know how it goes!

Eric W.