You can set one up, but it is not automatic. If you have cruise control, you can jump 2 pins on the ECM and get fast idle at 1200rpm & 2000rpm. It is actually the control for the PTO, but works as a fast idle.
A long time ago, I bought the PPE fast idle kit. It works pretty good, but you have to hit the cruise control to get the engine to run up (not good for autostart, you still have to walk out to the truck).
You could also do it w/ EFI, and tie it to ECT, but I have never done it. I was always afraid of pushing through the brakes if I took off before the engine was warmed up and idle rolled back to stock.