Thermostat or water flow problem.
crankshaft sensor
Could be a failed engine coolant temperature sensor. Easy enough to replace and not too expensive.
Have fuel filter or fuel injector checked..
== ==
i have a 2000 dodge work van 318 engine when i start in the morning it stalls several times until it warms up then ok
air mas or lander sencor
check the thermostat dude may need replacing
seriously man it did that in my acura til i switched the main relay
Low Coolant or faulty gauge
temp senser or spark coil
at the beginning it will be cold, but it will warm up as you start driving
Could be low on coolant or a sticky thermostat.