90 tracker distributor vacuum advance bad idling issues

[Banned]

Thanks so much Fixkick for a very detailed answer and very much appreciate what you do for us,
this is what I've done since:

Replaced distributor w/remanufactured, for kicks applied vacuum 400mm and held.
Not able to do timing since idle's all over the place. The dizzy I replaced also had something loose inside, one of the
weights (springs) seemed to be loose, broken. Also the rotor spring back did not go back smoothly as does the new one.
After a few test drives the surge seems to be faster than before and after car warms up.

Yes the MAT (not IAT) was bad, had a big crack just like in the pictures you have on your site, vacuum is a pretty and mighty powerful force, no? and these are the chracteristics I recorded
in hot water: 70° = 2.34 Ω
104° = 1.63 Ω
140° = .77 Ω
176° = .38 Ω
212° = .21 Ω
ohms spiked severely at least once as water temperature rose between 140 and 176
MAT was replaced, also seemed to not have been tightened by previous bad guy and had a steel corroded washer that did not fit very well on center.

Today I was in hot water again as I've had suspicion of the ECT sensor or possibly the bad guy that installed the thermostat did not do it right:
ECT sensor test
Key on/motor off
Result: Voltage 4.71v Visually: ok
Characteristics:
Laser digital Thermometer
32° = 5.89 Ω
68° = 2.05 Ω
70° = 1.95 Ω
104° = 1.00 Ω
140° = .46 Ω
176° = .27 Ω

Analog Thermometer
32° = 5.88 Ω
65° = 2.66 Ω
104° = 1.36 Ω
140° = .59 Ω
176° = .35 Ω

Also today: Checked thermostat for proper installation, position and visual inspection.
Result: hot water test begins to open at 178°, full open at 180° degrees, weep hole to front and visually looks like a new part.
Also replaced wires with Bosch, nice fitting, the previous had corrosion even though they were replaced a few years ago, yeah some off brand junk, dizzy cap and rotor also new with good quality type.
CEL never goes on except when ignition on/motor off.
CODES: 12, 12, 12... all day and all night long for the last 5 years I've owned it. Never throws anything else even though it idles like a mongrel from hell.
ISC at 6.6 ohms and sealed nicely. ISC is only a few years old.
PCV test. at idle, placing finger over nipple, ticks and sucks replaced a few years ago..
Cleaned vacuum nipple at manifold for dashpot vsv vacuum supply and replaced vacuum hose
(nipple to vsv)
Re-grounded fuel pump ground at L tail lamp. Oiled fuel pump terminals at rear lamp housing and ground.
Checked engine grounds and ECM ground for positive contact.

Will test for fuel pressure and injector drip next after I reinstall the coolant thermostat and ECT sensor.
I tried the timing light on the injector with motor idling but could not see any fuel spray pattern...
also will try timing the darn thing if I can get it to idle at 800 for a few seconds which it does after warming car up and turning it off for about 10 minutes, it idles nicely but then it starts gaining speed until it reaches 2000 and then it starts its surging.