Is this idle characteristic a problem?

[Shinare]

I drive to and from work on the highway for about 20 minutes every day. Most of the time its 50-60 MPH depending on the traffic. On the way home I cruise for about 5 minutes at 65'ish before taking an off ramp that ends directly at a red light. As in leave highway, foot on brake until the light. I've noticed that when I get stopped at the light after exiting, my car idles weird. It sounds like its idling a tad high maybe, but it sounds OK, but then the idle will drop down so low it almost sounds like the engine catches itself from dieing and when it catches itself it revs up to what I might expect would be normal or a little high. Then it dips down and catches itself. Repeat several times or until the light changes to green. Its like this every day. One day a while back it did actually die on me and I had to restart.

Mechanically I have a completely stock Yaris 3 door hatch back with manual transmission.

[eTiMaGo]

AC on?

[ROCKLAND TOYOTA]

I drive to and from work on the highway for about 20 minutes every day. Most of the time its 50-60 MPH depending on the traffic. On the way home I cruise for about 5 minutes at 65'ish before taking an off ramp that ends directly at a red light. As in leave highway, foot on brake until the light. I've noticed that when I get stopped at the light after exiting, my car idles weird. It sounds like its idling a tad high maybe, but it sounds OK, but then the idle will drop down so low it almost sounds like the engine catches itself from dieing and when it catches itself it revs up to what I might expect would be normal or a little high. Then it dips down and catches itself. Repeat several times or until the light changes to green. Its like this every day. One day a while back it did actually die on me and I had to restart.

Mechanically I have a completely stock Yaris 3 door hatch back with manual transmission.

my car does same thing and NO a/c is not on......

[Shinare]

Not unless for some reason, even if the AC button is off it kicks on. Thats the first thing I thought of but I made sure it was off.

[eTiMaGo]

Happens here too (and there's been many other threads about this in the past), I think it's just due to the very low idle speed of these cars. the variable speed is normal (it's mentioned in one of the technical manuals), but yes it is a bit scary wen it seems to get close to the stalling point then picks back up... and running the AC only makes the effect stronger.

[severous01]

could be alternator fielding in. full field has been known to stop a diesel engine in it tracks...any way, could be alternator

mine does it too...but i just assumed it was dramatized by the lack of an actual motor mount. i'd love to have mine filled with poly...but noone will get back to me anywhere i've tried to contact.

[why?]

Happens here too (and there's been many other threads about this in the past), I think it's just due to the very low idle speed of these cars. the variable speed is normal (it's mentioned in one of the technical manuals), but yes it is a bit scary wen it seems to get close to the stalling point then picks back up... and running the AC only makes the effect stronger.

exactly. All these cars have a weird, non-linear idle. mine has never died on me, but does everything else you said.

[Shinare]

The one time it died on me at that light I was driving pretty "aggressively" (high RPMs) and if I remember correctly I came to a pretty quick stop. Then the RPMs went down to what I was expecting would be idle, did the dip in idle, and it died. Started right back up, but it worried me enough that I haven't been that hard on my poor Yaris since.

Just hoping I haven't done something that made it do this weird idle thing. Thanks for the info guys. Gives me a little confidence that there's nothing wrong.

[severous01]

are you guys auto or manual? could have a problem with the torque converter lockup solenoid? maybe hangin up if it's dieing when coming to a stop. or, a sticking idle air control valve/motor.

i'm a manual, but i'm still having the issue....not bad, but still annoying. any way, i sprayed some moc cleaner on my TB and it cleaned it up a little. my idle smoothed out...and there was oil in there pretty bad. i think i'm gonna do the catch can thing and try to keep it cleaned up a little more.

[Altitude]

I seem to recall a little bit of this when I first bought mine. But I haven't experienced it in a long, long time.

[yaris2010RS]

mien only does it when the a/c is on and when im cruising at 60km+ and push the clutch in and hold it in. it will fluctuate between ~400rpm and ~1100rpm...... other then that not when im stopped

watch first part of video, after a while i jsut start messing around. and sorry for the phone quality

http://www.youtube.com/watch?v=pEb1NY1xSXU

[Altitude]

Check this thread (http://www.yarisworld.com/forums/showthread.php?t=31656&highlight=idle+speed)

And this one (http://www.yarisworld.com/forums/showthread.php?t=25752&highlight=idle+speed)