ORIGINAL: Sport_Pilot
I understand that you are not familiar with process control systems.
Or you don't understand proportional control systems. A regulator and controller are not the same by the way. A regulator does not take an outside input for one.
Sport Pilot,
In control systems, or a part of it, the most important fact is range ability. Range ability, the limits of operating within the accuracy we want.
The range ability of all the parts of the system does gives the useable range of the system. (Your throttle range?)
For example the low idle flow through the control valve of the regulator for a four stroke engine.
If this flow is not within the wanted accuracy controllable, we have to design a better control valve in the controller or even a new controller.
If a proportional control loop isn’t accurate enough there are other possibilities.
A more complicated controller (P&ID), two controllers, master slave controller, pump controller combination (Walbro?) etc
Of course you also can start with a pump, pump controller combination, pump and a more complicated controller (P&ID), pump and two controllers etc.
When you only use a pump, the fuel air ratio (dosing?) does has its limitation of accuracy in low and midrange, but also the limitation of max RPM. So I prefer a controller.
For the designer there is one important limit!
An engine might never quit!! Also not after 2 minutes idle as you write in post 30, that’s a bad (de)sign for an engineer, so back to the drawing board when there isn’t a fault in the system.
Cees