IAC motor pintle always open?

[FE 065]

Out of curiosity, I disconnected my IAC motor hose from the air box, then revved the engine a bit to see it the pintle inside the IAC motor closes completely once above idle speed.

It doesn't ! There was still just about the same amount of suction present at 2500rpm or higher as at idle.

While my service manual says the PCM adjusts the IAC based on various inputs, none of the listed inputs has anything to do with the car not moving or mph...

Doesn't the IAC close at all once underway? Anyone know more about that - more than the apparent obvious?

Maybe the Wizard knows..

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[2001 GTS]

The wizard knows all...but I would like to know the outcome of this too.

 

[Viper Wizard]

Maybe the Wizard knows..

You must be registered for see images attach

That's great, Thanks!!

To your question, no the IAC never closes all the way! The PCM & O2 sensors are adjusting for that vacumn leak. At an idle then the IAC starts to move to mantain you idle anywere from 550-750 RPM. Your idle is a controled vacumn leak.
Hope this helps?

 

[viper spray]

The tip of mine kept coming unscrewed and messing up my idle , a new IAC fixed it.

 

[FE 065]

That's great, Thanks!!

To your question, no the IAC never closes all the way! The PCM & O2 sensors are adjusting for that vacumn leak. At an idle then the IAC starts to move to mantain you idle anywere from 550-750 RPM. Your idle is a controled vacumn leak.
Hope this helps?

Thanks Chuck

 

[Jack B]

Out of curiosity, I disconnected my IAC motor hose from the air box, then revved the engine a bit to see it the pintle inside the IAC motor closes completely once above idle speed.

It doesn't ! There was still just about the same amount of suction present at 2500rpm or higher as at idle.

While my service manual says the PCM adjusts the IAC based on various inputs, none of the listed inputs has anything to do with the car not moving or mph...

Doesn't the IAC close at all once underway? Anyone know more about that - more than the apparent obvious?

Maybe the Wizard knows..

You must be registered for see images attach

You need a scan tool to track/log the IAC.

 

[RAYSIR]

Also the throttle position sensor sees the above idle and has no reason to close. Getting ready for the close of the throttle.