"TeGGeR®" > wrote
> Of these, the EACV and the Fast Idle Valve are warmed by
coolant. Their
> inlet and outlets are respectively connected to the
discharge and suction
> sides of the cooling system, so flow through these items
appears positive,
> and self-purging of air.

If the EACV or its cooling lines are a high spot, then air
will tend to accumulate there, regardless of what pump is
sucking/pushing coolant through its passages.

> Coolant feed through the EACV appears to be there solely
to prevent icing
> of the EACV's air passages. Coolant temperature does not
control the EACV
> in any way.

I wouldn't conclude this without more evidence.

Regardless, it's air in the system that I think is behind an
EACV /not being properly cooled/ and so not functioning
correctly.