Difficulty to start early morning

If I remember correctly, the OBD 1 port was under the hood on early Troopers

Check that ALL vacuum lines are connected, and properly.

You may want to take a hard look at your Coolant Temperature Sensor.

replacing the head gasket solved one problem.
But, you have a leakage problem with oil and/or antifreeze now.
The head gasket could be failing again, or you have a cracked block or cylinder head.

Take it back to where it was worked on and say that you want it fixed, please.

good luck on this.

The power steering fluid level is low or the v-belt tension needs adjusting.Its not likely to be the aircon comp.Look at the v-belt.Adjust if needed and also see its not cracked or too shiny that would allow slipping.If in doubt,replace it.It will be the problem.Hope this helps

It would appear your thermostat is stuck in a open position. Good luck this is an easy fix. Go ahead and change your coolant while changing the thermostat; use a new gasket too. Total cost for this will be under $20.
Please let me know if this assisted you.
Thanks,
To,

You might check the engine computers coolant sensor value as this incorrect parameter could be the source for your symptom

I have a 1990 trooper for sale for $400 bucks, only thing wrong with it is the starter, 2.8 V6, great for parts.

Lock all doors..Then with the key unlock passengers side door then it should stop..

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_a3369546f8067589

Well, could be many things, but first and easiest, check the dist. cap and rotor, and all the plug connections. Any moisture will freeze and short out the ignition system. Also change the fuel filter. If you get the slightest moisture in the fuel it will lock up the filter when the water freezes. Could be a relay, probably "engine relay" that sticks when it gets too cold.

Some starting points I hope.