fcom 1.70.80
ENGINE VENTILATION (dry cranking)
A dry cranking cycle ventilates the engine to remove fuel vapors after an unsuccessful start attempt on the ground.
The flight crew can manually select cranking, by setting the ENG MODE selector to CRANK and the MAN START pushbutton to ON (MASTER switch OFF). The flight crew can stop the cranking by setting the MAN START pushbutton to OFF.