common ignition switches have 4 positions:
off
accessory (usually just radio)
run (with power to ign and all accessories)
crank (with power to ignition)
When you crank your car the radio, wipers, heater etc all stop working until the key returns to run. So obviously your ecm and fuel pump need to be powered on crank.
to illustrate, the picture below is the ignition switch connections for the ~86 camaro with tilt column I used in my truck. I'm not sure what purpose the wires that go to ground on crank have, I ignored them.
