Preheat oven to 350º.
Combine 1 cup sifted flour, 1/2 cup margarine and 1/3 cup finely ground pecans. Blend to crumb consistency. Press in even layer in bottom of 8" square baking pan. Bake in preheated oven 20 minutes, til very lightly browned. Cool
Drain juice from can of unsweetened crushed pineapple and add water to measure 2 cups.
Soften 1 envelope unflavored gelatin in 1/4 cup water.
Prepare lemon pie filling with 1 pkg. (4 3/4oz) lemon pie filling with 3/4 cup sugar, and 3 egg yolks, reducing liquid to the 2 cups pineapple juice and water. Cook until smooth and thick, stirring constantly. Remove from heat and add softened gelatin, stirring till dissolved. Cool 10 minutes, stirring occasionally.
Preheat oven to very hot (500º)
Fold 1 cup sour cream into pudding mixture and turn into cooled crust.
Prepare meringue and spread over filling.
Meringue: Beat 3 egg whites with 1/2 teas. cream of tarter to a fine foam. Gradually beat in 1 1/4 cups sifted powdered sugar, continuing to beat at high speed until very stiff and shiny.
Place in very hot oven, turn heat off at once and allow torte to remain in oven for several hours, till it is completely cold. Remove torte from oven, and sift powdered sugar over top. Chill several hours before serving.