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96 Seville
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Discussion Starter #1
I saw a reference to the "Pintle Valve" needing to be serviced to correct a rough idle. ....I think it was Ranger that posted it. I see in the "How to fix it" how to remove the IAC solenoid for cleaning but no reference to the "Pintle Valve" . Can someone explain it's location and procedure for removal/repair please. Thank-you.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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The IAC is an in/out motor - the pintle, the black top hat plunger - controls idle air bleed around the throttle butterfly. You remove the IAC assembly, insure that the top hat is screwed onto the shaft, and then clean it all judiciously with throttlebody cleaner - as well as cleaning out the IAC TB bore with fuzzy pipe cleaners from a craft store.

There's also a pintle on the EGR motor.

pintle - a tapered calibrated movable "plug" ???

https://www.google.com/search?q=pintle+valve&ie=utf-8&oe=utf-8
 

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96 Seville
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Discussion Starter #3 (Edited)
So the IAC motor once removed will expose the pintle end which may on occasion vibrate loose and require hand tightening. The failure of the pintle end will cause a similar rough idle condition similar to a dirty IAC solenoid. Do I have this right ?

The reason why I ask is that my 96 STS does have a rough idle ....not to the point of stalling but not what I would call a velvet smooth idle. I'm looking at cleaning the throttle body and would clean the IAC solenoid and at the same time check the IAC motor pintle end......please advise .

Another question ...the IAC motor turns in/out in response to what? Is it controlled by the IAC solenoid? .....sorry for all the dumb questions !

Later: after some thought I'm thinking that the IAC motor and IAC Solenoid are one in the same ....correct? I understand how a solenoid works ....opening and closing a switch .....but didn't think of it as a "motor". Its purpose is to control idle air bleed in the TB .....but what sends it information to make it change positions?
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,270 Posts
So the IAC motor once removed will expose the pintle end which may on occasion vibrate loose and require hand tightening. The failure of the pintle end will cause a similar rough idle condition similar to a dirty IAC solenoid. Do I have this right ?

The reason why I ask is that my 96 STS does have a rough idle ....not to the point of stalling but not what I would call a velvet smooth idle. I'm looking at cleaning the throttle body and would clean the IAC solenoid and at the same time check the IAC motor pintle end......please advise .

Another question ...the IAC motor turns in/out in response to what? Is it controlled by the IAC solenoid? .....sorry for all the dumb questions !

Later: after some thought I'm thinking that the IAC motor and IAC Solenoid are one in the same ....correct? I understand how a solenoid works ....opening and closing a switch .....but didn't think of it as a "motor". Its purpose is to control idle air bleed in the TB .....but what sends it information to make it change positions?
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after some thought I'm thinking that the IAC motor
and IAC Solenoid are one in the same ....correct?

no -
two completely different parts -
that work in two completely different methods -
that are responsible for basically the came task -
adjust idle speed -

the ISC - Idle Speed Control motor physically moves the throttle plate -
to control idle speed -

the IAC - Idle Air Control solenoid is mounted directly on the throttle body -
it has a plunger that moves to open or close an air passage within the TP -
 

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96 Seville
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Discussion Starter #5
Submariner409 refers to the IAC Motor ...which I'm assuming is the same as what others refer to as the IAC Solenoid.....that is my question. I made no reference to the ISC motor.
 

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White Diamond '03 DHS (with DTS floor shift)
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It is technically called the IAC "valve". The IAC valve rarely needs cleaning. It's the TB that gets filthy and causes a rough Idle. Clean that first and see what happens.

The black tip id the pintle.


Can someone explain it's location
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Yes, two completely different things -

The later motor is a stepper system that changes the IAC bleed in response to idle load changes.

The earlier ISC solenoid is - a solenoid - that physically moves to change the throttle stop screw position in order to affect idle due to engine idle load changes.

If your engine has an ISC then it has a throttle stop adjustment solenoid. If your engine has an IAC then it has a stepper motor to adjust air bleed around the throttle plate - using a pintle.
 

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Discussion Starter #9
Yes it has the IAC valve. I've been busy with family matters.....hate that when it interferes with playing mechanic! I will clean the TB and check the IAC valve when I get my life back. Thank you for your help on this.
 
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