what's that old saying? "a pat on the back works wonders when applied young enough, often enough, and low enough"
seriously, i understand if you don't believe in spanking, but there should be some form of discipline, and 34 months is past old enough to understand directions and consequences. try a time out corner, if you don't believe in physical discipline, and if you do believe in it, lightly bop his mouth and say "no tantrums" in a firm voice when he wails--one time. if he continues, pick him up, set him in his room, and close the door until he calms down. explain on your way there that he disobeyed, and now he needs to stay here until he can control his temper, and then say nothing else until the matter is closed. then, hug him, talk to him, etc.