Yaris fast idle

[tallpaul]

When it's cold outside, but the engine is well warmed, my 1.0 Yaris idles faster than norm, around about 1000rpm.

If I dab the throttle, it'll drop back down to normal again. At the next set of lights, the whole game starts again.

Any suggestions as to what's causing this ?

It doesn't happen all the time, just occasionally.

Cheers, TP

[tallpaul]

I looked again, its actually about 1500rpm.

TP

[Oli]

Things driving the alternater will make a difference. In the cold you will have your heaters on which would cause a higher idle level.