Having troubles with my '89 4Runner - 3.0L V6, Auto, 175K. Idle speed has jumped to ~1600rpm (~1000 in gear) and stays higher than normal while driving and there are occasional stumbles while driving (like fuel or spark has been interrupted momentarily). Sometimes the rpm's drop to 300 or 400 then go back to about 1500 in a repeating cycle. This only happens when in Park or Neutral and I press the brake pedal. The same thing happened once before and I traced this problem to the brake light switch (can't explain what was happening though). I played with several things to correct the high rpm's, including unplugging the cold-start injector, cleaning and resetting the TPS, and resetting timing. Something worked, but only for a couple of weeks. I put match-marks on the TPS body and distributor housing when I finished last time & neither has moved. Anyone got any ideas? Thanks!!!