There are a couple of ones that do OK in sun if acclimated to it over a period of time. I think Hoya 'Ruthie' is one. However most all hoyas do not do well in much full sun. The leaves will burn or turn very pale yellow. A lot of them can take early morning sun or dappled (as under shade trees) sun. It makes a difference, also if it is inside the house. Most do great in Eastern or Western facing windows, and some are fine even right in a South window as light in the house is never as strong as outside.

thanks ill try find a shady spot somewhere outside for them then