-20F (real temperature, not "wind chill") is not cold enough for a vehicle in good condition, winter-weight oil, and winter-blended fuel to fail to start.
Carburetor or fuel injection--doesn't matter. (Assumes the carb has a properly-functioning choke.)
I don't know what was accomplished with the five seconds for the vehicle to "think". I'm more likely to believe it was coincidence; or an additional fuel-priming cycle.
He also said he boosted it several times before it started.
Did it slow crank the first time?
Weak or frozen battery. Bad connections etc.
Did you crank it over and over again and it got slower and slower?
Hot starter.
Dont keep cranking on the starter when it turns slow thinking that it is the battery though it does drain the battery pretty quick.
The starter is a high reduction motor and they get really hot really fast.
That is why you can crank an engine and it gets weaker and weaker untill it wont crank at all.
Then if you wait a few minutes it will kinda crank again.
That is not the battery rebounding though it kinda does.
That is the starter cooling off enough that resistance in the windings drops.
Probably coincidental, probably accumilated heat from cranking.
But cold wire energizing is a really big part of aviation starts.
You often key on a circuit to warm it and to test it.
When you power a wire its resistance changes with heat.
And the feedback from that sensor changes.
These trucks are obviously not built to aviation standards.
But they are from that same generation of systems development but have a much looser and cheaper "out of bounds" set of parameters.
Plus, if you have a sketchy connection someplace.
Key on and off and a jump box might just warm that up enough to make it work again.
It has nothing to do with letting it "think about it"
Thats just a term he used to describe what his results were after the whole episode.
Im cold as hell reading this and its 18 degrees above zero here.