You just turn the ignition barrel to start and stop the engine.
The Sun
And then, shortly before it remembers that it's an engine, you give up and turn the ignition off again.
Times, Sunday Times
Turn the ignition key and the real drama unfolds.
The Sun
Turn the ignition on for two or three seconds before firing up, so the electronics can get going, and only then try starting.
Times, Sunday Times
Turn the ignition key to the 'on' position for two or three seconds to allow the electronics to get going, then engage the engine.
Times, Sunday Times