Toyota carina idle rpm issue

dev89 · January 25, 2017

Hi All,

My car is having a strange idling issue and the exact problem is as follows.

After starting the car (when it is cold), rpm settles around 1300 and rpm doesn't get lower after engine got to the operating temperature. No matter how long the car runs, it stays around 1300. Few weeks ago this system was working fine. cold start rpm was around 1300 and after few mins it settles around 800-700. Now it doesn't work like that, but if I turn off the car and start it again when hot, then rpm settles around 800. If I leave the car for few hours to cool down and then start it, again rpm get stuck around 1300.

So the issue is cold start rpm get stuck around 1300 and it doesn't get lower unless restart the car. If I restart the car when it is hot, then rpm settles around 800.

Is this could be a possible ECU failure ? Any expert ideas ?

Toyota Carina Ti 1997 MT ( 220000 kms )

Thanks in advance.

Edited January 25, 2017 by dev89

PerfMad · January 25, 2017

When was the last time you did an Engine tuneup? better to get an engine tuneup done (if it isn't performed recently). And get your engine checked for any error codes as well as a startup..

Twin Turbo · January 25, 2017

Paying particuliar attention to your air mass meter.

have a complete diagnosys of the engine p.s. when did you last change the air filter?

dev89 · January 25, 2017

Performed an engine tuneup a week ago. Changed the air filter and the plugs as well.

Twin Turbo · January 25, 2017

On 1/25/2017 at 7:52 AM, dev89 said:

Performed an engine tuneup a week ago. Changed the air filter and the plugs as well.

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Cleaned the throttle body,.?

PerfMad · January 25, 2017

On 1/25/2017 at 9:49 AM, Twin Turbo said:

Cleaned the throttle body,.?

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good point.. any idea what are the things carried out throughout the process ?

dev89 · January 25, 2017

On 1/25/2017 at 9:49 AM, Twin Turbo said:

Cleaned the throttle body,.?

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Yes, cleaned the throttle body, injectors, fuel pump etc. That's why I was thinking about an ECU issue. Even if the throttle is stuck, how come the issue get fixed after restarting the car ( when hot).

PerfMad · January 25, 2017

Could it be an issue with the sensors like MAF or IACV ? cz to me it looks like something is sending incorrect values to ECU..

Davy · January 25, 2017

If they disconnected the battery before the tune up, it could be that the ECU was reset and is still learning. How many Kms have you used the car since the tune up? Usually the system learns within about 20 Km depending on how the car was driven. So if it's only been a few Kms, put a few more and see if it solves the issue.

If not, it's probably due to the idle air control valve sticking. Some mechanics have a habit of spraying throttle body cleaner directly on IACVs and some units go bad as a result. You just need to properly clean the IACV using a clean rag dampened with TB cleaner and making sure the motor operates normally without sticking.

I wouldn't assume it's the ECU without even checking the above and performing many other tests to eliminate other causes.

PerfMad · January 25, 2017

On 1/25/2017 at 11:02 AM, Davy said:

If they disconnected the battery before the tune up, it could be that the ECU was reset and is still learning. How many Kms have you used the car since the tune up? Usually the system learns within about 20 Km depending on how the car was driven. So if it's only been a few Kms, put a few more and see if it solves the issue.

If not, it's probably due to the idle air control valve sticking. Some mechanics have a habit of spraying throttle body cleaner directly on IACVs and some units go bad as a result. You just need to properly clean the IACV using a clean rag dampened with TB cleaner and making sure the motor operates normally without sticking.

I wouldn't assume it's the ECU without even checking the above and performing many other tests to eliminate other causes.

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yup agreed.. unless you can borrow a compatible one just to plug in and check for free

Rumesh88 · January 26, 2017

1300 RPM with AC on or off?? What happens to RPM if you start car when hot with AC off and RPM settles at 800 then switch on AC?

dev89 · January 26, 2017

On 1/26/2017 at 2:33 AM, Rumesh88 said:

1300 RPM with AC on or off?? What happens to RPM if you start car when hot with AC off and RPM settles at 800 then switch on AC?

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1300 RPM with AC off.

If I start when hot without AC, rpm is around 800. If I turn on the AC, RPM settles around 850. Actually a very small difference. Now it's more than 750km after the tuneup.

Rumesh88 · January 26, 2017

On 1/26/2017 at 5:30 AM, dev89 said:

1300 RPM with AC off.

If I start when hot without AC, rpm is around 800. If I turn on the AC, RPM settles around 850. Actually a very small difference. Now it's more than 750km after the tuneup.

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Seems your IACV is getting stuck towards its end of movement. I'm sure whoever did the tune up did not take theIACV out to clean it. It is not a rocket science for a mechanic to check IACV for free movement of its flap.

Edited January 26, 2017 by Rumesh88

dev89 · February 27, 2017

Update...

Found that TPS is bad and replaced it with a reconditioned one. No rpm issues anymore.

Thanks everyone for the help.

Ramadhan Hamza · February 14, 2023

Carina Ti rpm problem

Ramadhan Hamza · February 14, 2023

On 2/14/2023 at 8:49 AM, Ramadhan Hamza said:

Carina Ti rpm problem

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Please help me

iRage · February 15, 2023

On 2/14/2023 at 8:50 AM, Ramadhan Hamza said:

Please help me

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Well...I think a lot more info would help...

What Carina is it ? What engine ? What exactly do you mean by RPM Problem ?

Depending on what is happening it can be anything from a vacuum/air leak, a problem with a sensor, problem with the air intake, a stuck throttle body, a...well you get the idea.

So, please do explain the issue to the best of your ability.

Edited February 15, 2023 by iRage