Gary,
The way to initiate the test, according to my book at least, is to wait until the KOER test is complete and clear, and then you give the accelerator pedal a 1/4 tap, and then the test will start.
It's very noticeable when under test...the RPM's ramp up, and the engine misses and shakes as it drops each cylinder out individually. It does each cylinder, about 5 seconds each with about 5 seconds between each test.
You'll get a code between 10-80 if it finds a cylinder out of balance, and a code 90 if they're all good;).
That's cool!
I don't remember that test when I tested my Bronco.
Speaking of which, I haven't had my tester hooked up forever. Everything has just been working.