I have a 1993 grand marquis that has a '93 302 mustang motor in it. Because of that I am unable to find anything on google because its not the 4.6L that was factory with that year model. Well I have had issues with it in the past and have fixed them all until now. Changed the valve cover gaskets
changed the upper intake gasket
changed the spark plugs and wires
changed the oil and filter
changed pcv valve in rear of motor

Now my issues are that it has a bad miss to it and runs rich, after run down the road and warmed up it dies out at stops and wont idle, and when i crank it and its idling i take off the oil cap and smoke is coming out. Im no mechanic so everything i google i try and im running out of money to guess fix it. It has high mileage but since the odometer doesnt work im unsure of how many miles. What can it be? Does anyone have any ideas that could help please? Im at my breaking point with life for many different reasons and my living situation isnt so good. So this car is my only way of getting anywhere. I just have no idea how to fix it since idk whats wrong with it and cant search for answers. I cant afford a mechanic or shop and cant even get any answers from anyone that ive asked in real life. This is my last hope of fixing it for fear of not being able to and what it might break inside of me.

Im sorry i have personal issues and no help with that either nor anyone to talk to. So take it as you will but i cant understand why ive always bent over backwards for most people just to have them stab me in the back. So this car is basically my only grip left to sanity. Lol.