I think your timing chain has maybe jumped a few teeth. My buddies '85 4runner was just like that and it was about 12 teeth off on the timing gear. Tried all kinds of tuning before taking it apart but nothing worked. Just had to put the timing chain back right with some new guides and a good timing chain tensioner.
This symptom could be caused by the throttle position sensor being off, but I'll bet it's your timing chain...
