Ford Repair: carborator, fuel mileage, ford f150

Question
i have a 1986 ford f150 i have to pump the gas to start the engine. After starting and putting in reverse it shakes and sputters.

Answer
what size engine is in this truck-most 86 models were fuel injected
except for bigger engines which had 4bbl carbs-i would need more info
like do you get black smoke when it starts-has your fuel mileage dropped drastically-is the check engine light coming on-after it is running how good is it? let me know so we may can zero in on possibilites of problems.