SMinn560sl, you're discouraging me.

If you've done all that effort and still have the same problem, then I may just settle for my current 1000 rpm warm idle.

Honestly, I didn't pay attention when I bought my car a few years ago and note how it idled back then. It definitely got worse a few months ago, easily reaching 1500 by itself (no stumbling though). With the Throttle Valve Switch recently replaced, the engine sounds "normal" to me.

Armed with Strife and other's suggestions to date, I have a few more things to check (alternator output, OVP, Oxygen sensor, temp sensor) before I give up on this task for now and move on the next item of concern for me...timing chain & guides health.

BTW, both my old and new Idle Speed Air Valve's were VDO brand and had the same threaded insert as dpetryk's photo. Here's a picture of my dissected ISAV showing the inside of the business-end: