EACV and fast idle valve

ICE_D16Z6

New Member
Hi guys,

I have two questions...
upload_2016-10-25_22-18-54.png
The civic workshop manual states (point 2 above) that the EACV is opened to control the fast idle speed. Isn't that done by the fast idle valve instead?
I mean, is point 2 above wrong?

The second questions is:
The coolant flows through the fast idle valve and towards the EACV while the coolant doesn't get to the normal operating temperature. Once it gets to the normal operating temp, the thermostatic element in the fast idle valve closes and the coolant can no longer flow through, right?
What's the purpose of having cold coolant flowing through the EACV valve?

Thank you.
 

Attachments

ICE_D16Z6

New Member
Hi boofoo,

Thank you.

1)
The ECU cannot control how much air flows through the EACV/IACV, can it? It can just be fully open or close, right? The reason I say this is: EACV is a solenoid valve, meaning it's either fully open or close.
If the IACV is open at low coolant temps, then there should be an "abrupt" (like vertical drop in the graph above), depending on how fast is the solenoid valve, change in the engine speed when the valve is commanded close, should there not?

2)
Doesn't the thermostatic element in the fast idle valve close when the coolant gets to normal temp? It closes the air passage for sure as the idle speed decreases at normal coolant temp, and it closes it air tightly as there is no vacuum at all in the intake (Throttle Body) lower port connected to the inlet of the fast idle valve.
 


Last edited:


Top