If there are vaccum lines to the distributor. There is probably a temperature switch in the head for Dist vaccum closed at start up and open at operating temp. If engine is morning cold and you feel sucking at the dist line that switch is bad. You can also clamp the dist vaccum line closed to start and unclamp it when car warms up a bit. That switch is a ported vaccum switch
If it has no vaccum line to dist. or sometimes no dist. there is a sensor.
If stuck open and trying to start with switch opens creates a bad misfire and wont start.
If switch is closed engine will run like crazy at start and quit at warm up.
Timing is everything
Thats a place to start after the basic.
If you live in a climate where it is cold. It might not start for work in morning and almost start when ya get home and drive ya crazy.