What should I do to get it de-mothballed before driving? Most fluids changed out at non-dealership. Old gas still in it. Car in great shape, new battery, drove it 40 miles and now fights starting.
It might be the gas. Did you use whatever fuel may have been in the car? If it’s the original fuel, it may have clogged the fuel filter.
I would suspect the gas. How much is left in the tank? If it is less than ? I would try filling it up and see what happens.