Disconnected the ICV tonight and the revs increased to 1700rpm as expected.

Reconnected and the revs dropped to 1100 or a touch less.

Have already checked all the air hoses, most are new.

Searching here for idle control module or unit only returns a couple of people who talk about resoldering some joints but little detail on exactly what's involved.

How do you check the output of the ICV to see if what it is outputting at idle is correct?

Cheers
Matt.