perhaps the washers allowed a small amount of air into the system and for the motor to start the it had to self bleed the air before she fired .
Remembering going from some thing that's hot to cold creates a vacuum.
Much the same as a boat trailer going to a boat ramp after the drive there the cold water and the hot trailer wheel hub create a low pressure area inside the hub and it then tries to suck water into the hub.
Well that's what I get out of it South Ace