Had a first today... my fuel pump froze up.
It's a crankcase vacuum pump, so there is a line from the crankcase to the pump. and usually you get a little condensation in the tube, and it froze up right inside of where the tube connects to the pump, got some rubbing alcohol to dissolve the ice and that fixed it... probably have to do it again tomorrow. but soon enough the warm air from the crankcase will prevent it for a little while after you kill it. it'd been about 5 hours since i had driven it....