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Howdy. I just replaced the IAC valve 'cause my '99 Ram 5.9L wouldn't idle. Now she idles between 1800 & 2000 rpms with the new IAC. If I recall there is an adjustment procedure for newly installed IACs, but I have no clue what it is. Anyone know? Thanks
 

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IAC's are not adjustable, they come pre-set from the manufacture.
 

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It may be the throttle position sensor.

But before you go and replace that...on the passenger's side of the throttle body there is a small knock out plug that covers the factory set idle screw. Take the plug out and you can try adjusting the idle down.
 

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Usually if you install a new IAC and your idle is still off, means that theres something letting extra air in. IE, broke vacuum line, dried intake manifold seals, etc. Before you punch out that cover for that screw, take a look over.
 

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^^I agree^^

It sounds like you obviously had an idle issue that led you to replace the IAC. During that time you may have developed a secondary problem. However, it's been my experience that a vacuum leak usually lowers the idle, hence the suggestion to attempt to adjust the idle.

As suggested ^ do a once over, and try pulling a vacuum line to see if it lowers the idle. After the once over, and a vac disconnect, then try to lower the idle.
 

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Yeup Maddevils right... vac leaks cause it to idle high....
 

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New info on an old thread

The IAC is adjustable. You pull the spring retainer sleeve down and rotate the pintle to the proper length. Releasing the retainer sleeve allows the flat edge of the spring end to reengage the notched pintle. I don't know the factory spec to adjust to, however... but I did read in the service manual that you are NOT supposed to adjust the idle screw that sets the throttle body idle position.

Source: Service manual + I'm all up in it right now.

2001 Ram 1500 Sport 5.9L Magnum 4x4
Unknown lift height (approx. 8") on BFG 35x12.5R15 KM2s
 
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