4 cups cooked elbow macaroni
1 cup mayonnaise
1/4 cup distilled white vinegar
2/3 cup sugar
2 1/2 tablespoons prepared yellow mustard
1 1/2 teaspoons salt
1/2 teaspoon ground black pepperr
1 large onion, chopped
2 stalks celery, chopped
1 green bell pepperr, seeded and chopped