this is never a fold, it's not pretty when you have low fold equity, but the fact is you have enough equity vs even the nuts (and sets) made up by dead money to continue playing on.
Since he might be able to get away from a Q w/ 99 or a heart with KQ etc etc its better to put it in now. Esp. because he so rarely will have air here to let him put you in on a blank turn (and call)
Also, a push here does squeeze a tiny bit of fold equity, which is nice. The numbers, as well, in case you need to know... (although playing party 2k, they should be ingrained in your head)
to play on you need to put in basically 1175 to win a pot of roughly 3430. So you're putting in 34% of the pot.
Two worst case scenarios:
http://twodimes.net/h/?z=1261005
pokenum -h ah kh - js jc -- 9s th jh
Holdem Hi: 990 enumerated boards containing 9s Jh Th
cards win %win lose %lose tie %tie EV
Ah Kh 335 33.84 646 65.25 9 0.91 0.343
Js Jc 646 65.25 335 33.84 9 0.91 0.657
or
http://twodimes.net/h/?z=1261006
pokenum -h ah kh - ks qh -- 9s th jh
Holdem Hi: 990 enumerated boards containing 9s Jh Th
cards win %win lose %lose tie %tie EV
Ah Kh 419 42.32 562 56.77 9 0.91 0.428
Ks Qh 562 56.77 419 42.32 9 0.91 0.572
So needless to say, never fold this, but shove it in.