1983 Ford F-100 Needs?

First- get yourself a chiltons or haynes manual. Then start by process of elimination. The problem(s) is either electrical or fuel. Try to eliniate one before going to the next. Check the plugs for spark. If good- check other electrical componets that have a direct link to fuel consumption, then go through fuel system if needed. Because it has set for so long you may want to get the carb cleaned out.