Rev Range Of A Yaris When Idling

[matt37]

Hi

I have a 07 1.3 Yaris. When the engine is idling the rev range will drop from 600rpm to 500rpm after about 10 seconds or so, is this usual? The rev range when idling also seems to be affected by the outside Temperature.

Matts37

[Madasafish]

Yes.

[motoxxx3]

Hi

I have a 07 1.3 Yaris. When the engine is idling the rev range will drop from 600rpm to 500rpm after about 10 seconds or so, is this usual? The rev range when idling also seems to be affected by the outside Temperature.

Matts37

The ecu makes the engine run a little richer on start up which makes it idle faster (in the same way as an old fashioned manual choke would), and then leans out the fuel/air mixture as the engine begins to warm up. My 09 Yaris does it, and our Honda Civic & Mazda 3

[siray123]

It should hover around ~800rpm when fully heated up, cant remember on my d-4d think its 800rpm.

Actually by design for the first couple of minutes cars runs rich by default and idle high, whilst an air pump typically pumps air in to heat up the CAT to get the best emissions/mpg more quickly.