> What happens to the idle when you unplug the connector from
> >the idle control valve?
>
> nothing happens, but if i disconnect the tempII switch the idle goes all
> over the place
>
>

Hmmmm. If I recall correctly, unplugging TempII basically tells the ECU the
engine is cold, making it ignore the O2 sensor input (?) and use a "default"
richer mixture profile. I reckon one way to check that is to unplug only the
O2 sensor and force the ECU to "open loop" mixture profile, see if it goes
erratic then too. Sounds like maybe something to do with fuel or air
delivery rather than timing. Vacuum leak maybe?

-- 
John Bange
'90 Vanagon - "Geldsauger"