it's happened a couple of times, it doesn't seem to hurt anything, it's just really annoying, and the cop that pulled up next to me, thought i was trying to race him...anyways, at temps over 88c, the revs bounce from 1500-2000 until the car cools down to 87c. anyway i can fix this, or is it normal. the pfc, is on a 94 fd, with 99 spec turbos, dp, cb, cai, efini y pipe. thanks for the help

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-make-your-untuned-pfc-basemap-safer-idle-better-no-datalogit-needed-841706/ follow through the procedure I mentioned there first. You will lose any tune or settings you have on there, unless you own a datalogit to save the map.

 

The stock PFC Settings 3 Fan vs Water Temp is set too high like the stock ecu.
Set all three to around 85/86C. This will help prevent your problem in the first place.
Secondly with a Koyo "N" pass radiator you will never get above 86C unless it is summer and you are on full boost for a while.

 

The hunting idle you mentioned sounded more like you either forgot to cut the 4 wires (per PFC instructions) or you cut the wrong wires. Check again and make sure you cut the correct wire (looking from the connector to the ECU (not ECU to the wire).