Turn play with TP marginal kicker

[AlmightyJay]

MP1 is weird. He's loose (50% VPIP) and aggressive (13% PFR) preflop, passive on the flop and turn (0.67 and 0.73 respectively), but super aggressive on the river (4.0). However, I've also seen him bet some strange holdings (like a 3-bet on a K-high flop with K9 when it was capped preflop, or strange donk bets with A-high). So I don't really know how to handle his turn donk bet. Should you raise in this spot, or call down? Folding seems bad when he could be betting something bizarre.

Party Poker 1/2 Hold'em (9 max, 9 handed) FTR converter on zerodivide.cx

Preflop: Hero is CO with J[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, MP1 calls, MP2 calls, <font color="#666666">1 fold</font>, Hero calls, Button calls, <font color="#666666">1 fold</font>, BB checks.

Flop: (6.50 SB) J[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(6 players)</font>
BB checks, UTG+1 checks, MP1 checks, MP2 checks, <font color="#CC3333">Hero bets</font>, Button calls, BB folds, UTG+1 folds, MP1 calls, MP2 calls.

Turn: (5.25 BB) 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">MP1 bets</font>, MP2 calls, <font color="blue">Hero...</font>