1987 mustang 5.0 misfiring while accelerating?
Would suggest replacing fuel filter first. If you left car with full tank gas most likely OK. If not need fresh gas in tank. Also suggest oil and filter change, check inside air filter and exhaust for mice nests. Also most likely some lifters bled down while sat and will need to run awhile to refill, Check all fluids too, Hope tires aren't dry rotted.