I'm back. You can test the map sensor (which rarely goes bad), the Intake air temperature sensor, and the coolant temperature sensor by disconecting them and testing the resistance at various temepratures to se if they look right.
I started a thread last year that has a lot if good info in it at:
http://www.naxja.org/forum/showthread.php?t=899397&highlight=idle+speed+wanders
http://www.naxja.org/forum/showthread.php?t=905849&highlight=idle+speed+wanders
I would stop buying parts and start runing Multi meter tests to track down the real problem. Check the ohms resistance (jeep power off) between the battery negative post and the engine (valve cover or engine block) and scratch a clean spot on the engine or valve cover to get a good conact. It should read less than one ohm, if not you still have a ground wire conection problem somewhere. Do the same between the engine and firewall and the firewall and the battery negative post. All should about or less than 1 ohm.
Check the resistance at various temepratures of the two temperature sensors, one in the thermostat housing and the other in the intake manifold.
Try disconecting the TPS and start the car. Let me know if runs OK that way. Do not press the throttle with the TPS disconnected.
Also post some details regarding your experience.
Does it run after start up if your hold the throttle open some or does it die anyway??? That answer will help us pick between the IAC and the ballast resistor. If the ballast resistor goes bad, the engine will start and then die. If the IAC is bad (hanging up) in the closed position it will idle too slow and die unless you hold the throttle open wider than the idle stop does. IAC can sometimes be cleaned and oiled and start working OK again.
Also read over the pdf I sent you about the relearn procedure and problems with idles and poor performance during the computer relaern procedure, which could also be part of your problem since you have changed so many parts and barely run it since then. I would disconnect the battery for 5 minutes, reconnect it to clear the memory of all the old bad sensor data it has and is still using!
Get back with us with on any results you get as it occures.