Can anyone tell me what cars have fast idle valves which activate with the current on, and under normal running receive no current?

You want a 2 wire ICV. They work like a solenoid, and have a normal Junior Power Timer connectors;

Like This

A three wire ICV is variable.

Ebay is a great reference tool;

Ebay Reference (Example)

Cheers Richard, I just didn't know which way they work, reading the MS Setup stuff, some are powered closed, and some powered open, I'd rather have powered open, IMO the less live stuff when running the better.

Left field thinking --- you could use a 12 solenoid valve (loads on ebay) and a restrictor, or an LPG injector valve.