It's either passiflora vitifolia or coccinea. The flowers are pretty similar--the easiest way to tell them apart is by the numbe of lobes on the leaves. Vitifolia, the grape leaf passionflower, has three lobed leaves, and coccinea has entire leaves (one lobe).

yours looks like P. coccinea. P. vitifolia flower, which looks similar, has three-lobed leaves. so check the leaves: single-coccinea; three-lobed-vitifolia

sorry...didnt see the post before mine :P