his hands are basically 33 or draws, of which there are several: A4[img]/images/graemlins/diamond.gif[/img], 45[img]/images/graemlins/diamond.gif[/img], Ax[img]/images/graemlins/diamond.gif[/img]

He may also take your PF limp as a weak K, and is betting with KQ, but that is very doubtful.

However, with at least 4-5 combinations of cards that would fit that betting behaviour, and only 1 of them beats you, I would favor staying in the hand.

Personally, seeing as you have position. I would call and re-evaluate on a non-[img]/images/graemlins/diamond.gif[/img] turn. If a diamond comes, your decision is easy, and you save half your stack. If a non-diamond comes, you're in the same position, but with only 1 card to come. (In which case I'd take the oppotunity to push, and take my 80%+ chance with any holding other than 33)