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OnlineHelp, Mechanic
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2003 mitsubishi eclipse spyder: cyl..normal idle in

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My 2003 mitsubishi eclipse spyder 4 cyl is having idling problems. At normal idle in park the idle will go lower and sometimes die. When the ac is on the idle will drop and die immediately. When driving it will run ok but the ac will not kick on and off properly. At stops it will die with the ac on. Any help?
Hello and thank you for choosing Just Answer.

Just to clarify, is this problem ONLY present when the A/C is on or does A/C just make it worse?

Has the check engine light come on?
Customer: replied 7 years ago.
<p>It occurs when the AC is off. It will idle up and down between 500 and 900 rpm or so irradically. When you turn the ac on it's worse and it dies.</p>
Thank you.

The first thing to check is vacuum leaks. This would be the most common problem for this issue. I would suggest that you check around the intake manifold, and the throttle body. These are common places where vacuum leaks occure.

If you do not find any vacuum leaks you need to check the Idle Air Control Valve (IACV) which operates the idle. This valve opens/closes to keep the car running and at steady RPM's when the car is ideling. The valve is mounted on the throttle body and looks like this:

Customer: replied 7 years ago.
I had already checked for vacuum leaks and couldn't find any. I couldn't see the IACV on the throttle body. Is it on the underside of the throttle body? Also, the vehicle has very low mileage, does this part tend to go out or could it be loose wire or something else. I noticed the part is close to $300 for replacement.
The part tends to go dirty or the spring will start to give out. It is on throttle body (bottom) here is a picture. (The IACV is #2)

Click image to see an enlarged view
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