Thanks again Adrian
I did find a small amount of info on the MS forum, mainly guestimated flow rates based on BHP produced by the original engine.
My searching was interupted buy a new search.
Trying to find the operating range of the IAC stepper motors that I have found.
When I built the Megasquirt I opted for the stepper motor idle control as opposed to the original ford type idle control unit.
I did find a couple of stepper motors in self contained units that are ideal for the job. Rover K series unit & a Renault unit.
All I have to do now is find the tec data on them.