high idle

1998 SATURN SL2
106,000 MILES • 4 CYL • 2WD • AUTOMATIC
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ALBERTAMABISCA
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when started maintains 1900 rpm when driving and to a stop. after about 20 minutes or more it comes back down i took it to dealers they cleaned out throttle body and replace a throttle body switch it and still accelerates. what could i do to fix it myself?
Jul 5, 2010 at 1:44 PM
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SATURNTECH9
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Hello,

It soin slike they missed the IAC which sounds weak. Here are two guides that can help us fix this problem.

https://www.2carpros.com/articles/engine-idles-too-high

and

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

Check out the diagrams (Below). Please run this test and get back to us.

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Jul 5, 2010 at 4:05 PM
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ALBERTAMABISCA
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they replaced idle air control valve, cleaned throttle body bore and cleaned injectors they did not mentioned any codes that poped up.still had the same problem in the morning for .it wasnt cheap!Should i try replacing ects sensor? thank you very much
Jul 5, 2010 at 7:46 PM
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SATURNTECH9
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Lets run the codes to see what's coming up.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.
Jul 6, 2010 at 11:29 PM
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ALBERTAMABISCA
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well i replaced ects sensor now it idles a lot better in cold starts but now when driving sometimes it get stuck around 1900 rpm while in driving around and also when i come to a stop. and then it will run normal rpm. its weird can you help me? what else i can do to try fix it? No codes. thank you
Jul 18, 2010 at 4:04 PM
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SATURNTECH9
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It sounds more like the PCM is not working right I would try a rebuilt or used unit here is the location. Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Jul 18, 2010 at 7:14 PM
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SHANNON_PRIV
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A used PCM cost me $70.00 worked great!
Jan 22, 2019 at 11:33 AM
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JAXON BRADLEY
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So I have a 98 sw1 and it’s idling high between 1700-2500 and it still does it when it’s fully warmed up, any suggestions on to fix it?
Nov 3, 2019 at 2:13 PM
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STRAILER
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It sounds like you have a IAC motor that is not working correctly. Do you have a check engine light on? Here are two guides to help us:

https://www.2carpros.com/articles/engine-idles-too-high

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down these guides and report back.
Nov 4, 2019 at 11:59 AM