Engine idle is way too high?

Tiny
SINIKA74
  • MEMBER
  • 1997 TOYOTA COROLLA
Engine Mechanical problem 4 cyl Front Wheel Drive Automatic 161000 miles

I know toyotas like to idle high until the cats are warm but this isnt normal. Aware of the existing idle situation, I bought this car for $600 and it runs great other than the high idle. The lady who I bought it from had rear ended a truck with a trailor-hitch and the ball on the hitch bent the first radiator."oil cooler?". But it doesnt leak. And left the larger/2nd radiator undamaged. The only other damage was to the grill, both radiator fans were damaged and punctured the ac "evaperator can?" located in between the grill and the radiators on the driver side. Any and all help will be much appreciated. Thanks, Shane
Wednesday, January 13th, 2010 AT 11:24 AM

30 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 46,334 POSTS
Hello,

Its sounds like you have a piece of carbon stuck in the idle air control valve. Here is a guide to show you how to clean it and get back on the road. This is a common problem with Toyota.

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

and

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

Please let us know what happens.

Cheers, Ken
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Tuesday, May 9th, 2017 AT 1:19 PM
Tiny
HEYWATCHIT
  • MEMBER
  • 1 POST
  • 1996 TOYOTA COROLLA
  • 19,700 MILES
Hello:

1996 Corolla DX 1.8L 7A-FE, 5 speed, 197,466 miles

Idles correctly during warm up, but after warm up drops only to 1100-1200 RPMs. Oddly, less than.5% of the time, it idles correctly after warm up for short periods of time, almost always in warmer weather.

1. Cleaned the throttle body
2. IAC working (applied 12v - opens and closes freely)
3. Cleaned IAC thoroughly
4. Throttle cable tension correct
5. Operating temperature correct
6. Runs perfectly

Any suggestions?
Thank you.
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
DRCRANKNWRENCH
  • MECHANIC
  • 3,380 POSTS
Here is a diagnostic walkthrough for high idle. Just follow the link below;

https://www.2carpros.com/articles/engine-idles-too-high
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
DANSFRAZ
  • MEMBER
  • 9 POSTS
  • 1996 TOYOTA COROLLA
  • 164,000 MILES
I have a 1996 Toyota Corolla. I have a problem with it idling too high. When the engine is warm, it still idles around 1400 rpm. I read that this can usually be solved by cleaning the IACV, but I found that after I cleaned it, the problem still persisted.

I tried unplugging the MAP sensor as well, and the idle dropped while running. I just wasn't sure if this meant the MAP sensor was bad or if it was a normal occurrence. What else can I do to further troubleshoot this problem?

I love this site!
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
When did this start? I would clean/check IAC valve as that is the air supply for idle. Any vacuum leaks can cause high idle also.
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
DANSFRAZ
  • MEMBER
  • 9 POSTS
The car has idled high as long as I have owned it. I bought it used back in the summer and it has done it ever since. I cleaned the IAC valve and it didnt seem to change at all. What is the best way to check for vacuum leaks?
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
You can do a visual for broke/split cracked/loose hoses. You can spray a flammable substance like spray start around gaskets and parts to see if engine speed increases. You can do a smoke test and watch for smoke to be sucked in to leak. Also IAC valve may be bad so cleaning it dont help.
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
DANSFRAZ
  • MEMBER
  • 9 POSTS
As suggested, I replaced the IAC valve and the idle improved dramatically. Now it idles high for 5 min or so when cold and around 1100 when warm, much better than the 1600-1800 it had began to idle at.
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
SAACHI
  • MEMBER
  • 2 POSTS
  • 1996 TOYOTA COROLLA
  • 1.8L
  • 2WD
  • MANUAL
  • 150,000 MILES
This car has had a high idle since I bought it. I bought it at an auction, and it has had that and a check engine light since I bought it. The vacuum lines are good and I have installed a new IAC valve. Both of the diagnostic ports on my car do not connect with the engine scanner when I had it checked, so I can’t see what is causing the check engine light, and if it has anything to do with the high idle. I got a MAP sensor at a junkyard, which lowered the idle significantly, but caused the car to feel as if it was bogging or holding back, if that makes sense. At this point I’m thinking it may be a wire shortage. Any thoughts?
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

Is the Malfunction Indicator Lamp (MIL) or "check engine" lamp illuminated? If so, could you please pull the Direct Trouble Code (DTC)(s)? You will need a code for that and I have included this link below for you if you are unfamiliar with how to do this.

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

Please go through this guide, if necessary, and get back to us with what you were able to find out.

Thanks,
Alex
2CarPros

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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
SAACHI
  • MEMBER
  • 2 POSTS
The check engine light is on, but it doesn’t scan. I’ve been to O'reillys and a few other local places that have scanners, and they don’t connect with the car.
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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

Here is what I was able to pull up on your vehicle's Data Link Connector (DLC). The DLC pins are standardized as per OBD2 regulations on every vehicle, so use the wiring diagram that I have included in the diagrams to see where the pins go to on the DLC. You will be looking for an open or for high resistance on one of the circuits. You will need to use a multi-meter to do this and I have included this link for you if you are unfamiliar with how to use one.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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Thursday, January 21st, 2021 AT 1:41 PM (Merged)
Tiny
GMANW2K6
  • MEMBER
  • 12 POSTS
  • 1995 TOYOTA COROLLA
  • 11,300 MILES
I have a 1995 toyota corolla and it has a very high idle when starting I have replace the idle valve and the tps sensor I even had my "service engine" light check but it doesnt say anything about it what else am I missing?
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
It is equipped with a cold start to increase the idling speed when engine is cold. How high is the starting idle speed and after warming up, what is the idling speed?
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
GMANW2K6
  • MEMBER
  • 12 POSTS
Its pretty high even after its warms up but it clams down after im in gear
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Either there is a vacuum leak after the throttle body or the IAC is not working correctly. It could be stuck open more than it should and how high is pretty high?
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
GMANW2K6
  • MEMBER
  • 12 POSTS
Really high ive had it measured; it reads ova 2000 hpm but when its in gear it read inbetween 900 to 1000 hpm
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
You need to have the IAC inspected if there are no vacuum leakages. Did you check the PCV?
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
GMANW2K6
  • MEMBER
  • 12 POSTS
Pcv valve has been replace
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Have you checked the IAC?
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Thursday, January 21st, 2021 AT 1:42 PM (Merged)

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