4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

Idle issues

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Old 04-03-2015, 10:25 AM
  #11  
swarthyfellow
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When my IAC was not working correctly, if I disconnected the tube going into the IAC with it running, it would stall. When it is running correctly it would shutter but keep running. I don't know if that is safe or smart but that is how i would confirm it was working right after cleaning it.
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Old 04-03-2015, 01:00 PM
  #12  
sweetbeats
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Well now I'm confused...because there is no "tube" going to what I think is the IAC (the thing I'm pointing to in the pic a few posts ago). Just a single connector with two wires.
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Old 04-03-2015, 02:50 PM
  #13  
jwog666
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Originally Posted by sweetbeats
Well now I'm confused...because there is no "tube" going to what I think is the IAC (the thing I'm pointing to in the pic a few posts ago). Just a single connector with two wires.
there is a tube that is about 7/8" in the pic u posted, it connects to the body of the iac
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Old 04-03-2015, 03:07 PM
  #14  
sweetbeats
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Oh duh...

I was focused on a small vacuum line. Okay. Thanks.
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Old 04-29-2015, 06:18 PM
  #15  
sweetbeats
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Right next to where the IAC mounts on the throttle body housing is a tube that doesn't connect to anything, but has something stuck one e other end of it. Is that normal? The tube and the thing stuck on the end is pictured below. The "thing" is in my hand.

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Old 04-29-2015, 10:29 PM
  #16  
jwog666
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thats your pcv valve, thats supposed to be in a grommet in the valve cover, you have a large vacuum leak with that sucking non metered air from outside the crankcase. fint the grommet on the valve cover and reinstal, should fix u up
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Old 05-25-2015, 01:38 AM
  #17  
sweetbeats
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So what then is supposed to be connected to the nipple that's right next to where the IAC assembly bolts up?

Also, is the IAC motor supposed to do something when you apply power to it? When I turn the key to the accessories position, 12V is applied to the IAC. I can feel the IAC respond just slightly, but the plunger inside the IAC housing doesn't move at all. I did clean it out with carb cleaner.
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Old 05-25-2015, 08:57 AM
  #18  
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the iac has a fitting for a fresh air hose, this hose attaches to your air inlet between the throttle body and the maf, replace the iac if u suspect its bad, but keep in mind that you dont know if the pcm is commanding it to open when ur testing, and that you will have 12v there most of the time because its ground side switched(if i remember correctly)
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Old 05-25-2015, 11:42 AM
  #19  
sweetbeats
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I don't think I'm explaining this well.

Im not talk about the fresh air hose that attaches to the IAC. I know where that's supposed to go. I'm talking about the fitting on the throttle body housing right next to where the IAC bolts up. On mine there was a PCV valve attached to it (see pic a couple posts back) which I understand makes no sense. So I'm wondering if that should then just be capped off or if there is something supposed to be attached there. See the pic below. I'm pointing to the fitting.

And I don't know if the IAC is bad. That's what I'm trying to determine. When the car is started, 12V is applied to the IAC. When that occurs, the IAC does nothing on mine. I tested it connected to the harness on the car, and also to my bench power supply. Nothing happens when 12V is applied to the IAC. I can feel the slightest little something, like the motor is trying to do something, but nothing actually moves. Does this mean it's bad? What is it supposed to do when power is applied to it? Because mine does nothing.

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Old 05-25-2015, 05:09 PM
  #20  
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ok, thanks for the pic, first ? is there a pcv that is properly installed? mine doesnt have that extra port, if there are no other disconnected vacuum lines, and there is a properly installed pcv valve, then cap that port, and clear codes, then see how it runs. next, im not sure if jumping power to the iac will result in much of anything that is usefull as a test. when in doubt, replace it, especaally when its as affordable as that
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