Idle up and down

[kuma]

When trucks in park it idles up to 1100 rpm but in drive it idles back down any suggestions checked idle screw, not that. Also its a 1988 fj62 3fe thanks

 

[KLF]

Check the adjustment on the TPS (Throttle Position Sensor). Also check the timing.

 

[slcfj62]

Mine had the same issue. My Check Engine light was not on but I discovered that I had an error 51 when I put the ECU in diagnostics mode. See my short writeup on this thread:

https://forum.ih8mud.com/60-series-wagons/273855-fj62-3fe-idle-problems-finally-fixed.html