My intention was to isolate the original raiser since he was a shorty. Then guy behind me insta-minraised. I figured for sure he would bet the flop, that's why I checked. And I planned on getting all-in. Figured him for a weaker pair with a club or and Ace of clubs.

Should I have just led strong on the flop? turn push ok?

Party Poker No-Limit Hold'em, $ BB (10 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

Hero ($23.15)
CO ($81.83)
Button ($24.15)
SB ($14.65)
BB ($4.25)
UTG ($19.50)
UTG+1 ($34.09)
UTG+2 ($10.86)
MP1 ($21.63)
MP2 ($19.50)

Preflop: Hero is MP3 with K, A. SB posts a blind of $0.10.
2 folds, UTG+2 raises to $2, 2 folds, Hero raises to $5, CO raises to $8, 3 folds, Hero calls $5.86, CO calls $2.86.

Flop: ($24.07) 3, K, 9 (3 players)
Hero checks, CO checks.

Turn: ($24.07) 9 (3 players)
CO calls $12.29.

River: ($36.36) 2 (3 players)

Final Pot: $36.36