Idle Fluctuation due to aftermarket intake? - Toyota Yaris Forums

Galavoxx · 12-17-2006, 07:05 PM

Installed the Weapon Research intake just last month and now I have this intermittent idle fluctuation. It doesn't happen all the time but the symptoms are always the same. After the car is warm, rpms will rise to 900-1000 rpms and then drop to around 700-650 rpms. This will continue to happen as long as the car sits at idle. I usually notice it when I pull up to a stop light. As I said, this doesn't happen all the time. Was wondering if anybody else has this issue with any of the other intakes or if this is a common problem? From my experience with motorcycle carburation, this symptom usually means that the idle jet is too big. Since this car is injected, I have no idea why it might be doing this. Seems like it happens more when it's humid outside but that could be my imagination. I also have a custom cat-back magnaflow exhaust. This could also be part of the issue.

jcove · 12-17-2006, 08:00 PM

Quote:

Originally Posted by Galavoxx

Installed the Weapon Research intake just last month and now I have this intermittent idle fluctuation. It doesn't happen all the time but the symptoms are always the same. After the car is warm, rpms will rise to 900-1000 rpms and then drop to around 700-650 rpms. This will continue to happen as long as the car sits at idle. I usually notice it when I pull up to a stop light. As I said, this doesn't happen all the time. Was wondering if anybody else has this issue with any of the other intakes or if this is a common problem? From my experience with motorcycle carburation, this symptom usually means that the idle jet is too big. Since this car is injected, I have no idea why it might be doing this. Seems like it happens more when it's humid outside but that could be my imagination. I also have a custom cat-back magnaflow exhaust. This could also be part of the issue.

I'm not sure about everyone else, but I see this from time to time. I have a Vibrant Exhaust right now, but it was doing it a little before. doesn't seem to be a problem.

Nutzoids · 12-17-2006, 08:05 PM

I don't have a tachometer, so I don't know what the RPMs look like... I also have no Engine Mods... Just a Short Shifter Kit... But sometimes when my Yaris is fully warmed and sitting Idle at a red light... The engine starts shaking the car slightly... And it definitely has a rhythm to it! I was starting to think this was a normal thing in small cars, but this post has just made me nervous!

Spades · 12-17-2006, 10:13 PM

my yaris did it when it was stock, still does it after exhaust on it. exhaust didnt change it. something about the engines idle control...i noticed it does it at any time when at a stop when the transmission is in neutral and it is iddling...it normally sits at 800rpm...then it drops to 500rpm and the engine shudders and then it spikes to 1000rpm.

im sure its either normal or a recall that toyota will send out at a later date,lol.

Kaotic Lazagna · 12-17-2006, 10:21 PM

that has happened to me a couple of times, and my Yaris is bone stock.

Galavoxx · 12-17-2006, 11:21 PM

Ok. SO it's not something with the Weapon intake. That's good. I thought I might have an intake leak or something. It does make me wonder why this is happening though considering it happens to cars that are stock and that have mufflers and intakes. Maybe poor engine mapping or an overly sensative ECU. Electric power steering maybe?

I'd like to get a little further into this. Anybody else have this problem or who might have a possible explanation? Chris? Chino? eTima?

eTiMaGo · 12-18-2006, 12:00 AM

I don't really remember how it was before changing the intake and exhaust, but I think it is normal, especially as we have an electronic throttle, the ECU always does some tricks with it.

Plus, when idling, the ECU also alternates between a rich and a lean fuel mixture, this is to keep the catalyser working at peak efficiency, so it may also have an effect on the idling speed.

Galavoxx · 12-18-2006, 12:19 AM

Quote:

Originally Posted by eTiMaGo

I don't really remember how it was before changing the intake and exhaust, but I think it is normal, especially as we have an electronic throttle, the ECU always does some tricks with it.

Plus, when idling, the ECU also alternates between a rich and a lean fuel mixture, this is to keep the catalyser working at peak efficiency, so it may also have an effect on the idling speed.

interesting. Have you had this problem?

DTM_Yaris · 12-18-2006, 01:22 AM

It happens bone stock to all of us. Notquite sure why. It is in the stock programming.

eTiMaGo · 12-18-2006, 03:02 AM

Quote:

Originally Posted by Galavoxx

interesting. Have you had this problem?

Well I usually have the air conditioning running, so that itself will cause the idle to fluctuate, but when it's off, yes, it will go up and down over time. I really don't think it's anything to worry about.

Next time I drive I'll keep the AC off and double check to see if there is a relation between the AF ratio meter and the RPMs.

Galavoxx · 12-18-2006, 12:37 PM

After hearing that this is a common problem, I don't think it's anything to worry about in terms of potential mechanical issues. What bothers me is that this is a new car and as such there should be no idle fluctuation once the car is warm. Thanks for the input.

eTiMaGo · 12-18-2006, 12:58 PM

Sure, but as the saying goes, it's a feature, not a bug

TrancosRt · 12-18-2006, 01:25 PM

Quote:

Originally Posted by eTiMaGo

Sure, but as the saying goes, it's a feature, not a bug

It sure is! It's to let you know the car is till on :P. I remember the first time I gave a some friends a ride they were quite sure the car was off! :P

My car does the same thing too. Next time I go to the dealership for the oil change (bought the package) I'll ask the tech about it (if I remember).

mikeukrainetz · 12-18-2006, 04:21 PM

Mine does that as well, idles around 800-1000 then drops and shudders slightly. I cant imagine that is a built in feature for anything... I had the same problem with my previous car.
Funny thing is the Yaris developed this idle fluctuation about 10000km not right off the lot. Does the yaris use the throttle body for idle air control or is it a seperate valve as on other makes/models?

Galavoxx · 12-18-2006, 04:41 PM

I have no idea...

eTiMaGo · 12-19-2006, 01:18 AM

Quote:

Originally Posted by mikeukrainetz

Mine does that as well, idles around 800-1000 then drops and shudders slightly. I cant imagine that is a built in feature for anything... I had the same problem with my previous car.
Funny thing is the Yaris developed this idle fluctuation about 10000km not right off the lot. Does the yaris use the throttle body for idle air control or is it a seperate valve as on other makes/models?

As far as I remember from the technical manuals the idle is controlled by the electronic throttle.

H2XcapePod · 12-20-2006, 07:35 PM

yup...I noticed the same looping a while back and thought it was kinda sweet! Usually you only get that on tuned cars...the aspirations of a bone stock Yaris...

foxtrot685 · 12-21-2006, 10:31 PM

i have a scion xA and it used to do teh same thing when i first got it. im thinking its common with the 1NZ-FE. give it some time and miles and it should go away... mine did

12-17-2006, 07:05 PM	#1
Galavoxx View User's Garage Drives: Yaris Hatch Join Date: Oct 2006 Location: San Francisco Posts: 397	Idle Fluctuation due to aftermarket intake? Installed the Weapon Research intake just last month and now I have this intermittent idle fluctuation. It doesn't happen all the time but the symptoms are always the same. After the car is warm, rpms will rise to 900-1000 rpms and then drop to around 700-650 rpms. This will continue to happen as long as the car sits at idle. I usually notice it when I pull up to a stop light. As I said, this doesn't happen all the time. Was wondering if anybody else has this issue with any of the other intakes or if this is a common problem? From my experience with motorcycle carburation, this symptom usually means that the idle jet is too big. Since this car is injected, I have no idea why it might be doing this. Seems like it happens more when it's humid outside but that could be my imagination. I also have a custom cat-back magnaflow exhaust. This could also be part of the issue.

12-17-2006, 10:13 PM	#4
Spades The Hated One View User's Garage Drives: 07 White Manual Sedan Join Date: Sep 2006 Location: Oregon,USA Posts: 390	my yaris did it when it was stock, still does it after exhaust on it. exhaust didnt change it. something about the engines idle control...i noticed it does it at any time when at a stop when the transmission is in neutral and it is iddling...it normally sits at 800rpm...then it drops to 500rpm and the engine shudders and then it spikes to 1000rpm. im sure its either normal or a recall that toyota will send out at a later date,lol. __________________

12-18-2006, 12:00 AM	#7
eTiMaGo vroom vroom View User's Garage Drives: lil red 5-door Join Date: Sep 2006 Location: Bangkok, Thailand Posts: 7,744	I don't really remember how it was before changing the intake and exhaust, but I think it is normal, especially as we have an electronic throttle, the ECU always does some tricks with it. Plus, when idling, the ECU also alternates between a rich and a lean fuel mixture, this is to keep the catalyser working at peak efficiency, so it may also have an effect on the idling speed. __________________ The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish. - Robert Jackson Bye bye 1NZ...

12-18-2006, 12:58 PM	#12
eTiMaGo vroom vroom View User's Garage Drives: lil red 5-door Join Date: Sep 2006 Location: Bangkok, Thailand Posts: 7,744	Sure, but as the saying goes, it's a feature, not a bug __________________ The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish. - Robert Jackson Bye bye 1NZ...

12-18-2006, 04:21 PM	#14
mikeukrainetz View User's Garage Drives: 2006 Toyota Yaris Join Date: May 2006 Location: Canada Posts: 564	Mine does that as well, idles around 800-1000 then drops and shudders slightly. I cant imagine that is a built in feature for anything... I had the same problem with my previous car. Funny thing is the Yaris developed this idle fluctuation about 10000km not right off the lot. Does the yaris use the throttle body for idle air control or is it a seperate valve as on other makes/models? __________________ http://www.cardomain.com/ride/2336679

12-17-2006, 08:05 PM	#3
Nutzoids View User's Garage Drives: 07 Yaris Liftback Join Date: Nov 2006 Location: Philadelphia Posts: 938	I don't have a tachometer, so I don't know what the RPMs look like... I also have no Engine Mods... Just a Short Shifter Kit... But sometimes when my Yaris is fully warmed and sitting Idle at a red light... The engine starts shaking the car slightly... And it definitely has a rhythm to it! I was starting to think this was a normal thing in small cars, but this post has just made me nervous!

12-17-2006, 10:21 PM	#5
Kaotic Lazagna View User's Garage Drives: '14 GT86, '08 Vitz Join Date: Dec 2006 Location: Central Valley, CA Posts: 9,873	that has happened to me a couple of times, and my Yaris is bone stock.

12-17-2006, 11:21 PM	#6
Galavoxx View User's Garage Drives: Yaris Hatch Join Date: Oct 2006 Location: San Francisco Posts: 397	Ok. SO it's not something with the Weapon intake. That's good. I thought I might have an intake leak or something. It does make me wonder why this is happening though considering it happens to cars that are stock and that have mufflers and intakes. Maybe poor engine mapping or an overly sensative ECU. Electric power steering maybe? I'd like to get a little further into this. Anybody else have this problem or who might have a possible explanation? Chris? Chino? eTima?

12-18-2006, 01:22 AM	#9
DTM_Yaris Turbo Yaris Drives: 07 PW Yaris Join Date: Dec 2006 Location: Dulles, VA Posts: 82	It happens bone stock to all of us. Notquite sure why. It is in the stock programming.

12-18-2006, 12:37 PM	#11
Galavoxx View User's Garage Drives: Yaris Hatch Join Date: Oct 2006 Location: San Francisco Posts: 397	After hearing that this is a common problem, I don't think it's anything to worry about in terms of potential mechanical issues. What bothers me is that this is a new car and as such there should be no idle fluctuation once the car is warm. Thanks for the input.

12-18-2006, 04:41 PM	#15
Galavoxx View User's Garage Drives: Yaris Hatch Join Date: Oct 2006 Location: San Francisco Posts: 397	I have no idea...

12-20-2006, 07:35 PM	#17
H2XcapePod Drives: 07 Yaris LB Join Date: Aug 2006 Location: Maryland Posts: 43	yup...I noticed the same looping a while back and thought it was kinda sweet! Usually you only get that on tuned cars...the aspirations of a bone stock Yaris...

12-21-2006, 10:31 PM	#18
foxtrot685 Drives: Scion xA Join Date: Dec 2006 Location: Buckley AFB, CO Posts: 43	i have a scion xA and it used to do teh same thing when i first got it. im thinking its common with the 1NZ-FE. give it some time and miles and it should go away... mine did

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