What causes higher rpm at startup and then dropping?

And how does cooler temp raise rpm, air is more dense?

 

https://honda-tech.com/zerothread?id=344296

 

read through the whole topic.. doesn't answer my question..

i'm trying to see if anyone know why does it happen? Would like to hear more details..

Why does it start up high and goes down, why doesn't it just start up at rpm it going to end up? Is it caused by cooler intake air? what conditions or part(s) control that?

 

it is called the FIV (FAST IDLE VALVE), it is on the lower part of the TB (Throttle Body). It gets one line of coolant, so the valve knows when to open and when to close. It does this till the car gets to a certain TEMP. Some people remove it and say it's ok, i'm not 100% sure about it. I'm kinda doing a lil research to see how exactly works and then proceed to see if would cause any side effect removing it. IMO i don't like the idea of coolant flowing through my TB, but it's the system that Honda designed and i trust them.

 

thanks.. getting some idea now

 

glad i helped!