cruiser54

Unplug the sensor. Meter on ohms, probe red and black wire on sensor.

SatiricalHen

Looks like 5 ohms

cruiser54

I think it's supposed to be 8 to 12 ohms.

Suprmn

as far as your fast idle, I would make sure you have the appropriate restriction in the crankcase venting system. I upgraded to a newer valve cover and it uses a tighter restriction so my idle is low. if yours has no restriction or not enough, it might cause it to idle high.

cruiser54

Interesting idea for sure.

SatiricalHen

Brand new PCV and CCV in the valve cover. Ran the Jeep with a vacuum cap instead of the vent tube and it still idled high

cruiser54

There is no PCV.....

SatiricalHen

Sorry, that's just the term that was showing up in all of the threads when I was trying to find part numbers for the vents. I have the "air inlet fitting" at the front of the 4.0 valve cover attached to the intake lid and the "fixed office fitting" attached to a fitting on the intake

cruiser54

Okay good.
Unplug the fixed orifice fitting from the valve cover and put your finger over the opening.

SatiricalHen

The opening in the valve cover or the opening in the orifice? What should this tell me?

cruiser54

Orifice. See what the idle does.

SatiricalHen

There was a slight drop in idle, but that's to be expected when plugging somewhere air comes in, right?

cruiser54

I'd need to see if the result is the same on someone else's 4.0 Renix.
At idle, what does the engine do if you plug the hole above the IAC with your finger?

SatiricalHen

Since it's a HO TB it's hard to cover the whole hole with my fingers

cruiser54

I'm wondering if this high idle issue isn't because of the HO throttle body.