Hello forum members, this is my first post.
I have a 1995 F150XL with the 5.0HO motor in it. Automatic with overdrive and 2wd. 185K on the clock and really runs great with no leaks or rust.
I am experiencing a cold start stall. Here is what happens EVERYTIME the engine is cold. The colder it is outside, the harder it is to start.
I start the truck, the check engine light flashes 3 times. The motor starts instantly and in 30-40 seconds it stalls immediately. I restart and its good from then on. If its 15 degrees out it might stall twice. Motor runs beautiful after the cold start issues. Sometimes the idle will kick up for no apparent reason and drop back down to normal almost like the fast idle. If its warm out and I cold start the engine will run for 30-40 seconds and the idle will drop down drastically and almost stall but it catches itself in the last second. When its cold out it just stalls.
Here is what I replaced so far...
Spark Plugs
Cap and rotor
Wires
PCV Valve
Air Filter
Oil and oil filter
Fuel Filter
IACV
Serpentine belt and tensioner
a few vacuum lines that looked questionable
Seafoamed the intake
I checked for codes 3 times already and there aren't any. Its showing System Passed.

Does anybody have any suggestions on what I should be checking next? Since I am throwing no codes I am at a loss. I thought for sure that putting a new IACV would have done it but I was wrong.
I have read that maybe it could be the EGR valve needs cleaning. I know there are 2, the solenoid which is in the back of the motor near the firewall and the EGR valve that has the sensor in it which is in the front of the motor near the throttle body. What about the TPS or the MAF ?? I would think if it was one of these it would throw a code.
To me, it seems like there is an incorrect command being sent from the ECU regarding the air/fuel mixture on a cold start and its stalling the motor.
Bottom line is I don't know whats wrong anymore, its 15 degrees out and I really need to fix this cold start issue. Thanks!