Does anyone know why Toyota and some other OE's have fast idles on start-up and then drop to a normal idle after a period of time?
Like someone just hits a switch at the 30 second time limit and then it drops right off.
I'm assuming this is to circulate the oil and warm up the Catalytic / AFR's and 02's. My Highlander will run about 1,000 rpm on start-up I've noticed if the engine is below 100F water temperature and stay there for about 30 seconds before dropping off to normal idle. It also does this same period of time if it's bone cold from sitting overnight for example.
With my previous vehicles (Journey, Santa Fe, Ford Tempo) they would only idle faster in extremely cold weather only and then would slowly drop to 650 rpm sort of thing as the vehicle warmed up.
Just curious if anyone knows the official reason behind this setup versus the other.
Like someone just hits a switch at the 30 second time limit and then it drops right off.
I'm assuming this is to circulate the oil and warm up the Catalytic / AFR's and 02's. My Highlander will run about 1,000 rpm on start-up I've noticed if the engine is below 100F water temperature and stay there for about 30 seconds before dropping off to normal idle. It also does this same period of time if it's bone cold from sitting overnight for example.
With my previous vehicles (Journey, Santa Fe, Ford Tempo) they would only idle faster in extremely cold weather only and then would slowly drop to 650 rpm sort of thing as the vehicle warmed up.
Just curious if anyone knows the official reason behind this setup versus the other.