1986 Ford Mustang Engine Dies when it begins warming up.

This is a factory 5.0 sefi late year 86 lx mustang with a manual trans. I have added the mass air and computer from a 89 automatic mustang GT in the past. The problem just started recently, the car starts and runs fine cold. After it is driven enough for the temp gauge to hit about 1/3 the car starts cutting out. If i pull over and continue to baby it and do anything to keep it running, eventually when it reaches normal operating temp it goes back to running normal. After troubleshooting it a bit, now it has gotten so rough when it's displaying this problem that I am unable to keep it running long enough to get to that warm spot that keeps it running. It sputters, pops, even sounds like backfiring when i am giving it gas to keep it running. When it is parked in the garage, and warm enough to be problematic, if the car is started and no gas given, it will run for 2-3 sec and die. I have tried unplugging several items on the motor to see if there is any difference, and so far I have found none. These items include, IAC, Block temp sensor, EGR, MASS sensor. Any suggestions would be great.

Thanks

update.....
I replaced the IAC and it runs better during the warming period, but it still dies if left to idle and stumbles a bit if the motor is running at a cruising speed. It is less violent now when it dies, so it's better, but not fixed. Guess tomorrow I will replace the temp sensor. Codes I pulled from the computer after a reset and running until warm are as follows;

6 7
Improper signals are being
received from either the
Neutral Drive Switch (NDS),
Neutral Gear Switch (NGS),
Neutral Pressure Switch
(NPS), Clutch Switch (CS),
Manual Lever Position
(MLP) sensor or Air
Conditioner Clutch (ACC).
or,
Air Conditioner (A/C) on
during Self-Test.

8 1
Thermactor Air Diverter
(TAD or AM-2) solenoid:
circuit failure.
or,
Electro-Drive Fan: circuit
failure.
or,
Intake Air Control (IAC)
valve: circuit failure.
or,
Boost solenoid – circuit
failure.

8 2
Thermactor Air Bypass
(TAB or AM-1) solenoid:
circuit failure.
or,
Electro-Drive Fan: circuit
failure.
or, Electronic 4-Speed
Overdrive Automatic
Transaxle (E4OD):
Transmission Oil
Temperature (TOT) sensor
– signal voltage is too high.

9 5
Thermactor Air System problem – right (passenger)side air flow always upstream.
or,
Fuel Pump Monitor (FPM)
signal – indicates circuit
problem.