idle surging

[etniesfaction]

on my 97 gsx my idle is always at different rpms...also what is weird is when i start the car when completely cold the idle is below 1000 rpms when it should be around 1200-1300 rpms and slowly drop as the car temp rises to full warmed up...after warmed up and driving around for awhile at idle at lights or whenever my car idles at 1100rpms and randomly today the car started to surge from 1000 to 2000 rpms and there is no CEL...any ideas anyone

 

[Lusion972]

have you checked the ISC or the IAT? Go over your sensors, unplug and plug them back in one by one...if you find one that made no difference in it running then that may be the one.