Grease and flour Bundt pan. Sprinkle pecans into the bottom of the pan. Combine cake mix, rum, water, oil and eggs in a large mixing bowl. Beat 1 minute. Add pudding and beat for 2 more minutes.
Pour into the pan. Bake 50 to 60 minutes in a preheated 350° oven.
Boil sugar, butter, ¼ cup rum and ¼ cup water for the glaze in a small pan for 2 to 3 minutes.
Remove the cake from the oven. Immediately spoon hot rum glaze over the hot cake. Cool in pan 30 minutes before turning out onto cooling rack.