Poor idle speed when my engine is warm

2000 MITSUBISHI ECLIPSE
200,000 MILES • 2.3L • 4 CYL • FWD • MANUAL
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STRAYXIII
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I drive a Mitsubishi Eclipse 2000 2.3L.

In the past few days my car has started to idle horribly when the engine warms up. While it is cold, the rpms seem to be normal except for a small fluctuation up and down. However, once the car warms up, it comes short of stalling when it's on neutral or the clutch is depressed. Also, when it's warm there is a delay in the throttle response. However, i have noticed that if I raise the Rpms to 6000 (close to the redline) the idle returns to normal until I start driving again. After I raise the rpms and the idle returns to normal, the throttle response is normal.

Any help would be appreciated Thanks in advance!!
Feb 8, 2015 at 9:59 AM
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HMAC300
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 48,601 POSTS
It sounds like you have a vacuum leak which can cause the problem you are describing. Here is a guide you can use to help find the problem, please use this guide when the engine is cold only.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please go over this guide and get back to us.
Feb 9, 2015 at 7:08 AM
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STRAILER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 54,135 POSTS
I would start by doing an engine tune up, and replace the MAF sensor. Also clean the throttle bore and IAC motor. These two guides can help us with the location of the MAF sensor below.

https://www.2carpros.com/articles/throttle-actuator-service

and

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

Spark plug ID

NGK .................... BKR5E-11
Denso .................... K16PR-U11
Champion .................... RC10YC4

Also, ignition coils go out all the time on these cars so I would get a set of them as well. Check out the images (below). Please let us know what happens.
Jul 13, 2024 at 3:25 PM
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