Engine erratic or stalls when put in gear while engine still cold

2004 KIA PICANTO
203,455 MILES • 0.9L • 4 CYL • 2WD • AUTOMATIC
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PHALSOTHY
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Dear sir. I have a problem when I try to put in gear (D,R,1,2) while the engine is cold (morning start or engine getting cold). my car starts erratic or sometime it stalls but after the car warms up it is running smooth as silk. but still have fuel problem it kind triple my fuel consumption. Note: Transmission fluid changed about 2 years, engine fluid change 2 weeks ago.

Please help and thank you.
Nov 11, 2020 at 4:24 PM
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JACOBANDNICKOLAS
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Hi,

This vehicle isn't offered in the US. However, I will try to help.

When you say there is an issue when it's cold, the first thing that comes to mind would be the coolant temperature sensor. This sensor tells the computer how cold it is and then the computer determines the air-fuel mixture needed to run the engine.

If the check engine light is on, I would recommend having the computer scanned for codes. That should point us in the right direction.

Here is a quick video showing how it's done:

https://youtu.be/b2IJGfImVvw

If you have a scan tool that can read live data, check to see if the temperature sensor signal is close to the outside temperatures.

Let me know what you find.
Joe
Nov 11, 2020 at 4:37 PM
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PHALSOTHY
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Hi, Mr. Joe.

Thank you for reply, I'll check and change it today. My car didn't show any check engine light. I have try to check with my mini OBDII scanner.

Thank you, I'll reply my result soon.
Sothy
Nov 11, 2020 at 10:33 PM
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JACOBANDNICKOLAS
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Hi,

You are very welcome. I reread your original post. Since you are having poor fuel mileage, it could even be related to a faulty fuel pump regulator (pressure is too high). It's a theory at this point, but it wouldn't be a bad idea to check it.

Here is a link that explains in general how it is done. I'm adding it in the event you want to check the pressure. It should help.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know if that helps and what you find. Also, please feel free to ask questions because they may help me point you in the right direction.

Take care,
Joe
Nov 12, 2020 at 6:29 PM
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PHALSOTHY
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Hi Mr. Joe,

Thank you so much. Yesterday I have try to find the coolant sensor but it was out of stock all place now trying to find online. Yes thank you again I'll try to check as your advise.

Thank you.
Sothy
Nov 12, 2020 at 6:34 PM
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JACOBANDNICKOLAS
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Hi,

If you have access to a live data scan tool, you should be able to check the coolant temperature sensor's signal to see if it is accurate. I wouldn't want you to replace it and find that wasn't the issue.

Please feel free to let me know if you have any questions or need help.

Take care,
Joe
Nov 12, 2020 at 7:10 PM
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PHALSOTHY
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Hi, Mr. Joe, I have a mini scan tool and I try to check this is what I get. But actually I have test with idling my car with no air con turn on and wait if the engine fan running and yes the fan running as normal. So i thought may be the coolant temperature might be working normal but my scan tool not support with my car. Scan tool and result attach in photos.

Thank you.
Sothy.
Nov 12, 2020 at 7:58 PM
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JACOBANDNICKOLAS
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Hi,

I attached a copy of one of your pics below and circled two temperatures.

Was it -41° Celsius? Also, it shows 33°Celcius is the temperature of the air entering the engine. That is a really big difference.

Let me know if it was actually that cold when you checked this.

Joe
Nov 12, 2020 at 8:04 PM
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PHALSOTHY
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Hi, Mr. Joe. Thank you.

Actually here is 27-29 C, and I don't know why it doesn't change the temp, it is stuck at -41C even if try idling for about 10mn. And wait until the engine fan running as normal.

Thank you.
Sothy
Nov 12, 2020 at 8:17 PM
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JACOBANDNICKOLAS
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That is the likely problem. It is telling the computer it is -41°C and the computer is making the fuel mixture extremely rich so the engine can run under those extreme conditions. Basically, the engine is getting too much gas because it thinks it is that cold.

Replace the sensor and let me know if that takes care of the problem.

Take care,
Joe
Nov 12, 2020 at 8:20 PM
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PHALSOTHY
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Yes, thank you. here right now the sensor is out of stock most places and now trying to find it. Will reply back soon when i change and get the result.

Thank you.
Sothy
Nov 13, 2020 at 4:13 PM
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JACOBANDNICKOLAS
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Hi,

That sounds like a plan. I will watch for your reply.

Take care of yourself.

Joe
Nov 13, 2020 at 7:55 PM
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PHALSOTHY
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Dear Mr. Joe,

I just change the Coolant Temperature Sensor yesterday and now the problem is gone. Thank you so much for your help.

Can I ask you little out of topics? I just wonder what is purge control valve or solenoid use for? I just found out that my car was plug in the wrong tube for many years.

Thank you very much for you help.
Sothy
Nov 16, 2020 at 4:24 PM
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JACOBANDNICKOLAS
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Hi,

I'm glad to hear that is fixed.

As far as the purge valve, it is a component of your Evaporative Emission Control (EVAP) system. This system restricts the fuel vapor in the fuel tank from escaping into the atmosphere. Basically, it allows the vapors to be stored in what is called a charcoal canister to be burned by the engine when it is actuated to do so.

Regardless, I'm glad it's fixed. Please feel free to come back anytime in the future if you have questions or need help. You are always welcome here.

Take care,

Joe
Nov 16, 2020 at 8:11 PM
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PHALSOTHY
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Good Morning Mr. Joe,

The problem seem to come again after few days, The same problem just came up yesterday and the characteristic is the same but fuel consumption back to normal. what should I do or check again thank you for your help. Oh anyway I just found out that my obd2 Bluetooth not fully supported it say I need version 1.0 obd2 and what I have is 2.1 obd2.

Sothy
Nov 19, 2020 at 4:17 PM
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JACOBANDNICKOLAS
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Hi,

If there is a leak in the EVAP system, it could be causing the issue as well. You asked about the purge valve the other day. Have you taken care of that problem? Can you record what the vehicle is doing so I can see and hear it?

Let me know.

Joe
Nov 19, 2020 at 6:55 PM
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PHALSOTHY
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Dear Mr. Joe,

Do you mean you want to listen to the sound of the engine when it has the problem? Cos now I drive it for a while so the problem won't show up. If so I'll make a video at morning 1st start and sent to you. And the EVAP I have take care of it but only on the purge control valve just connect the tube to the right port.

Thank you,
Sothy
Nov 19, 2020 at 7:28 PM
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JACOBANDNICKOLAS
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Hi,

Yes, if you could do that in the morning, I would like to hear and see how it is acting.

Thanks,
Joe
Nov 19, 2020 at 7:52 PM
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PHALSOTHY
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Hi,

Thank you. I'll make the video tomorrow and sent it you.

Thank you.
Sothy
Nov 19, 2020 at 7:53 PM
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PHALSOTHY
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Hi Mr. Joe,

This is the video of my engine. But it not so good because I take it in a hurry afraid if the problem is gone.

Thank you.
Sothy
Nov 20, 2020 at 3:55 PM
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JACOBANDNICKOLAS
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That is good. The problem is several different things can cause an engine to act that way. Are there any odd smells such as a rich fuel mixture again? Have you rechecked the coolant sensor again to make sure the new one hasn't failed? Also, have you reconfirmed there are no engine vacuum leaks?

Joe
Nov 20, 2020 at 8:58 PM
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PHALSOTHY
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Dear. Mr. Joe,

For the vacuum leak I have ask the mechanic he said there is no leak, but can you told and show me how to check the vacuum leak. yes, I have recheck the coolant sensor it seems to work okay (recheck with mechanic) and no smell of fuel mixture again.

Is there any ways to check the coolant sensor with ohmmeter?

Thank you,
Sothy
Nov 20, 2020 at 9:16 PM
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JACOBANDNICKOLAS
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Hi,

Yes, it can be checked with a multimeter for resistance. The resistance will change based on temperature. Unfortunately, I don't have the specifications for your car.

Joe
Nov 20, 2020 at 9:36 PM
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PHALSOTHY
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Hi,

Thank you for your help. Sensor and vacuum I have ask mechanic he said working okay. But as I have a friend who use to drive this car he said may be the Idle air control actuator might be failing but that just he thought.

Thank you,
Sothy
Nov 20, 2020 at 9:44 PM
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JACOBANDNICKOLAS
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Hi,

The IAC is responsible for maintaining engine idle speed. Some can be serviced. Since you don't have any trouble when it warms up, that may indicate it isn't bad.

Here are a couple links you may find of interest. Note that the IAC is located on the throttle body. The first link explains how to service and the second how to replace (in general).

https://www.2carpros.com/articles/idle-air-control-valve-service

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

Let me know.

Joe
Nov 20, 2020 at 9:52 PM
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PHALSOTHY
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Hi,

Thank you so much for your help. I'll recheck the vacuum leak and recheck on the sensor will get back to you when I got result.

Thank you.
Sothy
Nov 20, 2020 at 11:11 PM
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JACOBANDNICKOLAS
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Hi,

You are very welcome. Let me know if I can help.

Take care,
Joe
Nov 21, 2020 at 8:35 PM