I have a very annoying idle during the engine warming up. The motor I have is a 96 LS in an EG, when the engine is cool, the idle jumping between 2K rpm and 1K rpm constantly until it get hot. Once the engine get hot it settle at steady 700-800 rpm. I've clean the IACV but it still jumping during warm up. Should I go ahead and clean Fast Idle Thermal Valve also?

Any suggestion?

 

it defenetely sounds like a FITV preoblem, but i tought that obd2 cars dont have them...
anyways, if you have one the white plastic screw inside prolly came loose.

 

I'll take a look at them when I get time this week. I just want to make sure, are you preffering to the valve mounted underneat the TB?
Thanks for the response