I have a 1988 Toyota Pickup - 3VZE. I have troubleshoot the symptom to the outside air temperature (not engine temp). Engine is at normal running temp with this problem. When the outside air is warm (above ~80°F) the idle will be low. When outside air is cool (below 50°F) idle is high, thus causing the idle fuel cutoff to engage at a stop sign with the brake on. Is the AFM (Air Flow Meter) the only component in the engine compartment that measures air temp? I have measured the AFM with a DVM and it vaguely falls within Haines manual temp chart.