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raising the idle speed?


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Dave, on the very front of the throttle body is a "can" shaped electrical devise that sits horizontal.

This, for future reference is the IAC valve (Idle Air Control valve).

Look on the passenger side of the throttle body just behind the can. In a recess sits a screw that also runs horizontal. This is the idle control.

 

The way the idle is controlled on fuel injected cars (turbos also) is to allow a small controlled vacuum leak. Not by adjusting how far the throttle plate is open as is the case on a carbed car.

This is mentioned for the sole reason that turning the screw anticlockwise raises the amount of the vacuum leak and thus increases the idle. (On a carbed car turning the idle speed adj screw this way lowers the idle)

 

Hope this helps, as you are correct- during the winter months, a slightly higher idle speed helps offset the battery drain caused by the heater blower, headlights and wipers all being used simultaniously at some times.

 

Note: the IAC valve controls the idle speed during warm up, but can affect the idle at all times if the internal shuttle sticks.

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  • 3 months later...

Hey...using the search works! I was aobut to post a new topic on how to lower my SPFI idle....time to go search out that screw.

 

Yay for the search feature!

 

Now if only my eyes can use its search feature to find that screw...

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