Gasoline can not be ignited by a spark, yes the movie guys take liberties with that one, lol
Gasoline VAPOR can be ignited by a spark
The "smell" of gasoline is the vapor, so if you can't smell it there is no vapor and when gasoline is cold..........less and less vapor the colder it gets
A gasoline engine needs minimum 30% gasoline vapor in a cylinder for it to fire
This is why you need compression above 100psi to get a good start, compression is HEAT, higher compression = higher heat = more gasoline vapor
Ever wondered why an engine needs to be Choked, even fuel injected engines, its to increase the Vapor level in the COLD cylinders
If cold gasoline is 15% vapor then if you DOUBLE the amount of gasoline you get 30% so engine can start, simple as that
Quick Start(starting fluid) is Ether in a spray can, ether has a lower vapor point and can be ignited by a spark, so in cold temps the ether can get cold engine to fire up.
Once a cylinder fires, it heats up quickly so the liquid gasoline coming in from carb or injectors is vaporized more easily to keep engine running
Block heaters really help for cold starts in low temps, more gasoline vapor as it enters the warmer engine