Idle Fluctuation due to aftermarket intake?

[muncher]

its the recirc valve ... uses exhaust air to heat up the air going to the intake

[El Jefe]

Originally Posted by muncher

its the recirc valve ... uses exhaust air to heat up the air going to the intake

ok lemme straighten some things out in the thread, i see alot of mis-informantion here

ok first off the yaris doesnt have a recirc valve, that is a part from the dark days of emissions control.

the problem the original poster is having is the a/c compressor kicking on and off, it seems like the computer is over/under compensating for the load change. i've noticed this on mine

the only way to fix this will be a reflash of the ecu to smooth the change out. toyota has no released this as yet and i highly doubt they will. it may be annoying but it causes no ill effect to the car as long as it's not stalling out or anything like that.

[Tamago]

clean your MAF

problem solved

[Galavoxx]

Originally Posted by El Jefe

the problem the original poster is having is the a/c compressor kicking on and off, it seems like the computer is over/under compensating for the load change. i've noticed this on mine

the only way to fix this will be a reflash of the ecu to smooth the change out. toyota has no released this as yet and i highly doubt they will. it may be annoying but it causes no ill effect to the car as long as it's not stalling out or anything like that.

But I live in San Francisco, I've never even used the a/c. I'm just satisfied knowing that this is a problem with more than just my car. I do agree with you though, I doubt Toyota will ever do a recall to fix the problem.

[Galavoxx]

Originally Posted by Tamago

clean your MAF

problem solved

Are you saying it came from the factory with a dirty MAF? I doubt it. I'll take a look though.

[Tamago]

if you've installed an aftermarket intake, the filters come oiled.. oil gets on the MAF and dirt sticks..

it's something to clean when you change your oil

[Galavoxx]

I can see how this would be a issue, though I've never had it happen on any other gauze/oil equipped car I've had. In my case however, I got the Weapon Research Foam non-oiled filter. Plus, this problem has occurred with other cars running a stock airbox.

[El Jefe]

Originally Posted by Galavoxx

But I live in San Francisco, I've never even used the a/c. I'm just satisfied knowing that this is a problem with more than just my car. I do agree with you though, I doubt Toyota will ever do a recall to fix the problem.

how often do you have your car in either of the defrost settings? that also turns the a/c compressor on even tho the little light does not come on.
try it out and let me know, test it with the a/c on or in defrost mode, and then with everything totally off.

[Tamago]

and any of those times did you check to see if the MAF was dirty?

[jcove]

Originally Posted by Tamago

and any of those times did you check to see if the MAF was dirty?

I don't have an aftermarket intake, and my car has done this from day one. It's not the MAF. I don't think it's the A/C compressor either, as I can't remember when my car didn't do this and I don't use defrost or the A/C 100% of the time. I think someone else stated this is something common to the 1NZ engine. It's not a problem as I have mine serviced at the dealer all the time. I've talked to them about a few things of interest, this included and I was told this was nothing to worry about and it's not a problem.

[Galavoxx]

Good to know.

[skc]

i have exact same problem. glad i'm not the only one.
at idle (when engine is warm) rpm drops to around 500 rpm from 700~1000 rpm.
I'm thinking it might be the header that cause this Idle Fluctuation (not 100% sure) due to change in oxygen content in the exhaust gases.
o2 sensor monitors the amount of oxygen in the engine's exhaust gas and send feedback to ECU if the car is running rich or lean.
i might be wrong but idle fluctuation started after installing MR header & gounding kit.
does anyone else with MR header have this problem?

[FlintS]

It is due to the low idle on these cars. Toyota figured if they lower the idle, then we will save more gas. When a fan engages the idle will spudder and change. Nothing to be worried about. I am sure in about four years we will all have to move up our idle....

[jcove]

Originally Posted by FlintS

It is due to the low idle on these cars. Toyota figured if they lower the idle, then we will save more gas. When a fan engages the idle will spudder and change. Nothing to be worried about. I am sure in about four years we will all have to move up our idle....

That's what one of the techs at the garage told me as well. Finally I remembered what he said. It was just a little while after I got the car so I couldn't remember what he said, just that it wasn't a problem. Thanks, that's been bugging me that I couldn't remember it!

[Slummy]

i just has my 1st service, and mentioned this issue, the tech said everything was "with in spec". idle was around 600.

[FlintS]

If you want it stop then move up your idle to about 750 or so. That way it only drops to 600 when the fan engages. You will lose slight fuel mileage though...

[Captain Slow]

I hate to bring up a super old topic, but I noticed this on the way to work this morning. First time it's ever done this, of course it's also the first time I've driven the car in sub-40 degree temperatures.

hoping it's only because it was so cold outside. it's pretty annoying to have your new car's idle dip and momentarily feel the engine shake and sputter.

if it doesn't stop I'll clean the MAF and report back here. if that still doesn't fix it I'll dig a little further into the problem and see if there is truly a solution other than raising your idle.

[cali yaris]

It's called rev hunting. Mine did that from day 1. It doesn't affect the car at all.