Q. Can you suggest some flowering vine in full sun?
My immediate thought is to plant a climbing hydrangea. Are you familiar with these plants? I had one when we lived in Rockville, MD. It was on a wall on the west side of the house. Here are some facts for you:
Hydrangea anomala petiolaris is one of the best of the ornamental vines and useful because it will grow and flower even in a northern exposure. This is a large heavy vine that requires a very sturdy support. Reddish brown, peeling bark is attractive in the winter.
CULTURE: Full sun or shade; needs afternoon shade in the Deep South and in western Zones 9 and 10. Plant in rich, moisture-retentive, well-drained soil. Climbs with the aid of rootlike holdfasts, which cling to almost any surface. Climbing Hydrangea's growth habit is unusual for a vine, because plants have lateral branches that will grow out as much as 3 ft from the supporting structure, giving a rich, deep texture that is quite unlike that of other vines, which more typically twine up a narrow support.
Prune as needed after bloom. No major insect or disease problems. Over-watering is a chief reason for losses. Space 5-10' apart.
GROWTH: Slow growing for first 2 or 3 years, but vigorous and fast growing once established (this is an example of that old gardener's saying about vines: first it sleeps, then it creeps, then it leaps. A little patience will be amply rewarded.). May take 3-5 years to start blooming.