you are way ahead. even if he has three unduplicated kickers with the case jack, you are still a big favorite. if there was a lot more money left you might want to play it different, but given that you are virtually all-in on the turn, no problem.
http://twodimes.net/h/?z=469537
pokenum -o ac qh js ts - kd jh 9s 8s -- jc jd 9c 5d
Omaha Hi: 40 enumerated boards containing Jc 9c Jd 5d
cards win %win lose %lose tie %tie EV
Js Ts Ac Qh 9 22.50 31 77.50 0 0.00 0.225
9s 8s Kd Jh 31 77.50 9 22.50 0 0.00 0.775