did you check to see if the brake booster has an adjustable rod that pushes into the master cylinder. I can't remember if integra's have that but it could be adjusted out to far and constantly putting the brakes on . to check, take the master cylinder out and the rod that comes from the brake booster see if it has a threaded end and a nut, then it is adjustable, if not then it sounds like your proportioning valve. let me know what you find out