Preheat the oven to 350 degrees F. Butter an 8 1/2 x 4 1/2 in. loaf pan and set aside.
In a large bowl, beat with an electric mixer the pumpkin, sugar, orange juice, eggs.
In a small bowl, combine the flour, baking powder, salt, and pumpkin pie spice. Add this to the pumpkin mixture, stirring until just combined.
Spoon 1/3 of the batter into the prepared pan. Fold the blueberries into the batter that remains in the bowl. Spoon the remaining batter into the prepared pan.
Bake 60 to 65 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and cool in the pan for 10 minutes. Remove from the pan and cool completely on a wire rack.