Combine sugar, flour and 1/2 teaspoon salt. Gradually stir in pineapple juice and eggs. Cook over moderate heat, stirring until thickened. Add lemon juice. Cool mixture to room temperature. Bring water, remaining 2 teaspoons salt and oil to boil. Add soup pasta. Cook until pasta is done. Drain, rinse and cool to room temperature.
Combine egg mixture and soup pasta. Mix lightly but thoroughly. Refrigerate overnight in airtight container. Add remaining ingredients, mix thoroughly. Refrigerate until chilled in airtight container. Salad may be refrigerated for as long as a week in airtight container.