Boil noodles 10 minutes in water, salt, and vegetable oil. Drain, rinse twice then cool.
Combine sugar, flour, 1/2 tsp. salt, pineapple juice from fruit, and egg in medium saucepan. Cook over medium heat until thickened. Add lemon juice and cool. Combine with noodles and refrigerate overnight in airtight container.
Add pineapple, oranges, marshmallows and Cool Whip.