Good Afternoon,
Basically my Mk2 16V idles at 2000 revs, once it's warm you can unplug the ISV and it's then fine but with it plugged in it just revs. So far it's been to 2 garages and they have checked pretty much everything, replaced the ISV etc etc, the diagnosis is the engine Thermo temperature control switch (see pic)...anyone else got any thoughts?

Also I cannot find a replacement anywhere, can anyone please help?
Thanks
Charlie