I actually have done this. Checked it with a multimeter and with a scan tool using live data, both installed, removed, but plugged in with engine running and removed completely. Every time the idle acts the same way and the TPS functions correctly.

 

So I have a good used MAF on it's way here. Found one in MA for $40 with shipping. Guess we'll see what happens.

 

No change in idle fluctuations. Tomorrow I pull the ECM and open it up. See if water is in there causing any problems.

To recap,
New IACV
swapped out MAF with another used, good MAF
TPS tested good
New ECT
Recent Tune-up(yes, 8mm wires)
Fuel temp sensor good
IAT sensor good
no vacuum leaks(checked multiple times going through 5 cans of ether total)
HO2 sensors reading correctly and testing good
Cleaned throttle body and entire air intake
All grounds pulled, cleaned and reconnected(they were all clean to begin with)

Am I missing anything here?

I had a thought tonight regarding fuel pressure...if my pressure relief is bad...can that cause it to spray too much fuel in through the injectors? I never did check my fuel pressure.

 

TPS and Stepper Motor were all I had...Please repost when you do figure it out?

I believe it could be the Fuel Pressure Sensor.....

 

got ambitious since there is no rain tonight and no wind.

Pulled the ECM, no moisture inside or remnants. Looks great.

Checked fuel pressure.
KOEO(key on engine off) 34psi(2.39kgf/cm2)
Engine at 2k rpms 27psi(1.898kgf/cm2)
Engine at 3k rpms 33psi(2.32kgf/cm2)

Rave has listed 2.39-2.672kgf/cm2(34-38psi) KOEO
Didn't find any specs for pressure while running.

 

For fun, here are the pics of my ECU.
http://smg.photobucket.com/albums/v6.../Land%20Rover/

 

Thank you for posting the pictures of the ECU.
I've taken a good look at the pics and haven't seen any problems.
Still... My '99 auto was having similar problems and it came down to a faulty solder joint inside the ECU, I had to use a loupe to see it.
You have changed the ECU and the problem persist so I'd start with the easy stuff first: check all the grounds you can get at. If resistence is encountered at the ground, the sensors will act up. I use special antivibration washers and dielectric paste (I used to hace a FIAT X1/9, I know about electrical gremlins).
An easy way to test a ground post is to connect a voltmeter between the Neg. batt post and the suspected ground wire. Contact resistance is proportional with load so measure voltage with load ON.
I've said before and i'm saying it again: I made a lot of money fixing electrical problems during university (1- bad contacts [crimps], 2- bad ground [rust], 3- bad wires [idiots using pins into the wire for continuity check])

SD

 

I just remembred that to temporarily treat the problem I just had to shut off the engine, remove the key and restart the engine: problem gone untill next drive.

SD

 

Got an ElmScan 5 to see if I could get better live data. That, and I finally got a code set. P1316, P1314 and P0304.

P0304 cylinder 4 misfire.

P1314 Misfire/catalyst damage
Location: Bank2
Cause: Engine mechanical fault, wiring, ignition/ fuel system, injector(s), MAP/TP/ECT/IAT sensor, EVAP system, ECM

P1316 Misfire
Cause: Wiring, other trouble code(s) stored, ignition/fuel system, MAP/TP/ECT/IAT sensor, injector(s), ECM

P1316 freeze frame states that it was running closed-loop, using O2 sensor to determine fuel mix.

 

So it tested the O2 sensors. The info is in the attachment.

Any thoughts related to this new info? I am too tired to think right now.