When I was a small child, early 60’s, I remember my uncles, then in their 20’s, were doing something like turning the ignition off and back on again while going slow that would cause a backfire on their 40’s and 50’s era automobiles.............
Autos in the ‘50s still had a manual choke. Put a spark plug in the exhaust, wired to an old ignition coil. Pull out the choke to get a really, really rich mixture. When ignited, it would explode and throw a 20 foot flame out the exhaust.
turning the ignition off and back on again while going slow that would cause a backfire
That was a very popular sporting event, back then.
Requires a stick or sufficient speed for the auto trans to spin the motor.
Today not many automatic will spin the motor, no rear pumps.
Today the fuel injection stops with the ignition.
But if you get grandma’s car up and moving, be very careful about the “off”, time.
Too much and the muffler takes the shape of a beer can that experienced a cherry bomb.
A common side effect.
And the launching of the mufflers!