UTG was Mp3? Right? It makes a big difference because he could have QJ QT JT. Hands he's not supposed to have when openraising from UTG. If he was UTG, i would easily fold the Turn. He could have have JTs QTs but most of the times he does have any pair. Kx most of the times. The important question is whether he could be openraising QT JT from MP3 because it's not according to the chart and if he's capable of openraising those hands it's not sure whether he semibluffs QT QJ. So if you do such analysis you should choose a realistic measure. It means: Leaving out these hands is wrong but consider them as 100% is wrong as well. Let's just check how many Semibluffs he must have that your calldown becomes beneficial.
So i did no assume that he's checkraising each 9x, kx obviously. that he's checkraising QTs QJs and JTo and does not have/checkraise QTo QJo. Many people don't actually dare checkraising the flop with just a gutshot when facing a 3bet preflop. so the amounts of combination seems reasonable to me. I got some strong hands in this range like AK and QQ but i left out KK AA. We don't know whether he sticks to a non capping strategy or whether he'S capping all his strong hands preflop so we have to put in some strong hands at least.
Board: K♦9♥8♠
Equity Win Tie
MP2 22.37% 22.19% 0.18% { AsJc }
MP3 77.63% 77.45% 0.18% { QQ-88, AKs, A9s, K9s+, Q9s+, J9s+, T9s, 98s, AKo, A9o, KTo+, JTo }
EQ is not that good but it's enough to peel the flop once and see what the turn brings.
TurnEQ:
Board: K♦9♥8♠ 9♠
Equity Win Tie
MP2 19.09% 19.09% 0.00% { AsJc }
MP3 80.91% 80.91% 0.00% { QQ-88, AKs, A9s, K9s+, Q9s+, J9s+, T9s, 98s, AKo, A9o, KTo+, JTo }
Almost 20%. Now the question is how much EQ you require to see the showdown. Quite easy:
Pot is 5,75 BB big. If UTG bets twice and you call twice, the pot will end up being 9,75. You have to pay 2BB for it so 2/9,75 = 20,5% EQ. So given people to even checkraise less with Gutshots, you should fold. Just with a particular that he's bluffing a lot and raising each gutshot etc you can call it down. Pretty close without reads but i'd fold the Turn. You just have 3 Outs against Kx and you're dead against 9x and his gutshots have still some outs against you. Not a favourable situation. 
