I remembered the Idle Speed Solenoids used on A/C cars to keep them idling at a stoplight with the AC on, and decided to adapt one of these to my car, to use as a Electronic Throttle. I mounted it up and adjusted it to increase the idle speed enough to keep it idling for a couple of minutes till it warmed up some. I did have to tweak the mount slightly, and enlarge hole for better access to the idle air screw. When the idle speed started to go up more, indicating the engine was warning up, I turned it off.
This allows me to get out, and close the garage and stuff while
it warms up.
Below are what I used on my 4150 style carb. Many differant solenoids will
work, but I found this one to be very well made, and has plenty of
travel to easily raise the idle to more than 500 rpms if needed. There is
another bracket that is much flatter, that has been miss packaged as a 20-9
but it will not work with a 4150 type carb.
The red arrows show where it mounts on the HP throttle base.