As contractions the difference between wouldya and wouldja
is that wouldya is an alternative form of wouldja while wouldja is eye dialect of would you.
wouldja
English
Contraction
(
en-cont)
* 2002 , Erich Segal, Love Story , HarperCollins, page 47:
- She screwed up her brow and frowned. "Oh Oliver, wouldja please?"