the base Gotech ecu has not got idle valve but you done need it on the escort rs turbo as you keep the stock one that is already there, which isnt actually an idle control valve, its a very "crude" air by pass valve that works off a temp sensor, and in turn switches off when warm.

an idle valve is only used on cold start to pull up idle from cold so once it has got warm then its not needed

the ecu can pull up idle in the ignition table to get around this if it has not got a idle valve like on a thotle body set ups. We have fitted gotech to hundereds of rst's over the years with great results.

If you wanted to run a PWM control for an idle control valve (not fitted to the RST as standard, however you can retro fit a Zetec one) then the gotech Mini X or Pro X have the control for this, with the mini x still using the hall effect pick up in the dizzy, hence keeping costs down on installation.

When we map the gotech mfi std, there are many correction tables, voltage, air temp and coolant temp, these all play a part with the idle, when they are set right the car will pull up its idle when necessary to prevent any cutting out, it is in effect its own idle control valve.

It is very rare we get a complaint that a car cuts out when idling, and when this is the case a quick call can soon resolve this.