RPM low and rough idle - Toyota Yaris Forums

kropekoi · 11-12-2013, 08:28 AM

Hi All,

I just had my vios (Yaris Sedan) serviced and I've already changed the air filter and cleaned the MAF sensor myselft. However, the RPM of the car is getting lower than 500 when I turn the AC on. On a cold start the car is idling roughly at 1k+ then it gets lower to 800 and it stays there, but when I turn on the AC it gets lower to 400 then the car starts to shake including the stick shift, and when the aux fan starts to run the RPM goes up to 700 then after a second it goes down again, and the aux fan turns off. It does this up and down rhythm for while (more than 5minutes) but when I drive and stops, it does the same thing. It did died on me a couple of times though.

But when I drive for more than 20minutes and I stop, it goes back to normal...

I need help from you Guru's, Masters, everybody! This is very annoying!!!!

TIA!

kropekoi · 11-12-2013, 08:30 AM

What do I need to do?

Someone told me to replace the Ignition Coil (which is expensive per piece), someone also told me to check the Idle Air Control Valve (which I have no idea if I can clean this or where I can locate this)

CTScott · 11-12-2013, 09:17 AM

I would try cleaning the throttle body, which contains the IAC valve. Carbon deposits in the throttle body can cause this behavior.

kropekoi · 11-12-2013, 05:15 PM

do you happen to know on how to clean the IAC valve?

11-12-2013, 08:28 AM	#1
kropekoi Drives: vios 1.3J Join Date: Jun 2010 Location: Philippines Posts: 34	RPM low and rough idle Hi All, I just had my vios (Yaris Sedan) serviced and I've already changed the air filter and cleaned the MAF sensor myselft. However, the RPM of the car is getting lower than 500 when I turn the AC on. On a cold start the car is idling roughly at 1k+ then it gets lower to 800 and it stays there, but when I turn on the AC it gets lower to 400 then the car starts to shake including the stick shift, and when the aux fan starts to run the RPM goes up to 700 then after a second it goes down again, and the aux fan turns off. It does this up and down rhythm for while (more than 5minutes) but when I drive and stops, it does the same thing. It did died on me a couple of times though. But when I drive for more than 20minutes and I stop, it goes back to normal... I need help from you Guru's, Masters, everybody! This is very annoying!!!! TIA!

11-12-2013, 09:17 AM	#3
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	I would try cleaning the throttle body, which contains the IAC valve. Carbon deposits in the throttle body can cause this behavior. __________________

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11-12-2013, 08:30 AM	#2
kropekoi Drives: vios 1.3J Join Date: Jun 2010 Location: Philippines Posts: 34	What do I need to do? Someone told me to replace the Ignition Coil (which is expensive per piece), someone also told me to check the Idle Air Control Valve (which I have no idea if I can clean this or where I can locate this)

11-12-2013, 05:15 PM	#4
kropekoi Drives: vios 1.3J Join Date: Jun 2010 Location: Philippines Posts: 34	do you happen to know on how to clean the IAC valve?