Car hunting after initial warm up

[jsmithcds]

79 911 sc
Car starts immediately
after a minute or so it starts hunting
after the motor gets hot the idle is fine at around 1k
and it runs perfect

After the car sits for 20 minutes it starts all over again after start up

Its like there is a certain engine temp range that the car wants to hunt

any ideas my mechanic is in Mexico till next week and I thought I would see what I could find from the experts.(fellow pelicanites)

any ideas?

[Flat6pac]

Tends to be running too rich if its hunting an idle
Just a thought
Bruce