[Steve '93ES]

That seems to be a pretty nice picture of your throttle position sensor.
The ICS is a bit lower, beneath the throttle body. Take the intake hose off and it'll be right there.
http://www.stealth316.com/images/isc_loc.jpg

 

[Steve '93ES]

I don't know anything about that brand, but the ONE review it has says it didn't work in a 3000gt.........
Defective ICS CAN damage your ECU. Cheap Chinezium parts may not be the best choice here.

The one most of us use (including myself) is this Standard Motor parts AC99:

More Information for STANDARD MOTOR PRODUCTS AC99

I see Amazon has it for a lot less but beware of counterfeits on Amazon. The pictures look a little rough to me and several reviews complain of quick failure.
I'm suspicious, I'd be cautious with that one.

Have you seen the Sticky about idle problems in the Turbo section?
Most of it applies to N/As as well. Worth a read before buying anything....

Idle problems? ALL about IAC in one place!

Care and feeding of IAC. First, the acronym identifications. IAC- Idle Air Control TB- Throttle body BISS- Base Idle Speed Setting ECU- Engine Control Unit Over and over and over again I see posts about idle problems. Strangely enough most seem to think an adjustment screw is the source of...

www.3si.org

 

[Steve '93ES]

I found out if I turn my temp unit on then the idle issues seem to be far worse.

That does kind of point to the ISC. When the AC turns on the ISC should bump the idle up.
If you have the defroster set ( the defroster turns the AC on ) when you turn the heat on and the idle goes down then yeah, classic ISC symptom.
You should ohm out the coils on your ISC as soon as possible to avoid damaging your ECU.
If it's not in that other link the "how to" is here: Stealth 316 - ISC Servo Motro

 

[Steve '93ES]

Progress! Good, I'm glad I didn't send you on a goose chase!
Does turning the AC on and off bump the idle up now? (make sure the defroster is off..)
With everything turned off (headlights, heat/AC, rear defroster, radio, etc), and your hands off the wheel, Is the idle steady but high, or does it fluctuate?
Trying to set the idle speed without a steady idle is a study in frustration.... You need to get the idle stable first.
Speedy's suggestions in that link should help.

If you do decide to try adjusting the idle screw be aware that the rubber "O" ring that seals it is over 30 years old now and is probably hard as a rock.
Turning the screw may crack it, causing a leak and making things worse.
The only place I know of that sells new ones is 3SX

Throttle Body Idle Adjustment Screw & Components

The world's oldest and largest 3000GT and Dodge Stealth Source for Performance, Maintenance, and Service

www.3sx.com

I try not to mess with that screw unless I'm sure it's necessary....