Preheat oven to 350 degrees. Prepare a 8"x4" loaf pan by rubbing the inside bottom and sides with butter then coating with a light dusting of flour to prevent the loaf from sticking.
In a medium bowl sift together flour, salt, and baking soda.
In a large bowl beat butter and 1 cup of sugar until light and fluffy. Beat in eggs one at a time, then add flour mixture and sour cream, alternating until completely combined. Add in 2 tbsp lime juice and lime zest and beat until combined. Gently fold in blueberries.
Spoon batter into prepared pan and bake till toothpick inserted in center comes out clean (60-65 minutes). Cover the cake with tinfoil halfway through baking to prevent the top of burning if it's browning quickly.
Remove from oven and let sit in cake pan for 10 minutes before removing to cool on a wire rack.
In the meanwhile prepare a simple lime syrup by adding 1/3 cup lime juice and 1/3 cup sugar to a small saucepan. Heat it until the sugar dissolves completely. Remove from heat and set aside.
Using a toothpick, prick the top and sides of the warm cake several times. Using a pastry or silicone brush, brush the simple syrup all over the top and sides of the cake and let it soak up. Then do it again.
Once the cake is cooled completely create a simple lime glaze by combining 2 tbsp of lime juice with 1 cup of powdered sugar. Whisk until smooth. It should be thick, but pour-able. Add more lime juice to make it thinner, or more powdered sugar to make it thicker. Drizzle and brush over the top of the cooled cake.
Cut into slices and Enjoy!
Notes
You can use a similar size pan if you don't have an 8"x4", just make sure to bake until done (check with toothpick).