Idle Speed Control Motor Connector

Tiny
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  • 1998 CHRYSLER CIRRUS
  • 125,000 MILES
How do you know if your car needs a new Idle Air Control Motor?
Friday, April 20th, 2012 AT 1:03 AM

9 Replies

Tiny
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Idle speed won't adjust or is too low after "minimum throttle" has been relearned after disconnecting the battery, or there's a diagnostic fault code and further testing shows the wiring to the motor is okay.

What's the symptom?
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Friday, April 20th, 2012 AT 1:06 AM
Tiny
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What type of testing needs to be done?
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Friday, April 20th, 2012 AT 1:24 AM
Tiny
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Very little. What are the symptoms, or why do you think there's something wrong with it? Failures are very uncommon.
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Friday, April 20th, 2012 AT 3:22 AM
Tiny
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It is like my gas pedal sticks and gets hard when I first put the car in gear or when I take off after a stop light turns green. Then I find myself having to press down hard to get it to move and then it sort of lounges forward.
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+1
Friday, April 20th, 2012 AT 3:33 AM
Tiny
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By "sticks", do you mean it physically is harder to press than normal or do you mean you need to push it further than normal to get going? Either way, that has nothing to do with the idle speed motor. I was thinking about testing it and in 16 years as a mechanic I never tested one. As an instructor I made my kids measure the electrical continuity but only as a small part of learning how they work.

If it feels like the gas pedal doesn't want to move freely, try it again with the engine and ignition switch off. If it is still sticking or binding, you might suspect a frayed throttle cable. If the binding only occurs with the engine running, suspect worn bushings for the throttle blade in the throttle body. Air flow and engine vacuum while running might put enough pressure on those bushings to make them stick if they're worn with rough spots on them. Either of those conditions are extremely rare so if replacement parts are needed, I would have no hesitation finding used ones from a salvage yard.

If there is or was an oil leak on your engine, dirt could have accumulated on the throttle cable causing it to stick. You could try rotating the throttle right on the engine. If it works freely, try lubricating the cable where it goes into the plastic casing. Silicone Spray Lube would be a good product for that. It goes on like water, soaks in, then evaporates and leaves a film of "slippery" behind. The Chrysler dealer's parts department has that product but you can find it in hardware stores and auto parts stores too.

Have a helper hold the throttle open on the engine, then try pressing the gas pedal. If it still sticks then suddenly releases, just replace the cable assembly. They are a very low failure item but every now and then we hear about one binding.

If the bushings in the throttle body are the cause of the sticking, that will likely affect the cruise control too. It makes very tiny adjustments as you drive to hold the car's speed steady. If there's some sticking in the throttle blade, the car's speed will change noticeably a few miles per hour before the cruise control servo relaxes or pulls hard enough to overcome that sticking. That gives the car's speed time to change too much and you'll see the speed creep up and down as you drive.
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Friday, April 20th, 2012 AT 4:35 AM
Tiny
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It does not stick when the engine is cut off. It only sticks when the engine is first started up or when I stop at a stop sign or stop light and then have to take my foot from the brake back to the gas.
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Friday, April 20th, 2012 AT 2:01 PM
Tiny
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That would indeed point to rough bushings in the throttle body. Definitely not common but not unheard of. I can pretty much guarantee you won't find one in stock at your local Chrysler dealer's parts department because they will have had very little call for it in the past.

Head to a pick-your-own-parts salvage yard. If you're anywhere between Ohio and southern Georgia, there's a dandy chain of very clean, well-organized yards called "Pull-A-Part". Customers and employees are very friendly and parts are REAL inexpensive but you have to remove them yourself. Take your own tools. You can do an internet search of their inventory at each yard to see if they have cars like yours but they don't list the engine sizes and they don't know what's already been removed from any car.
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Friday, April 20th, 2012 AT 8:15 PM
Tiny
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So what part am I going to get from the junk yard?
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Friday, April 20th, 2012 AT 9:28 PM
Tiny
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Throttle body. It's what the throttle cable pulls on.
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Friday, April 20th, 2012 AT 10:27 PM

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