Rough Idle on start after engine is warm

[mgroth]

2000 Boxster S Manual
71k miles

Car starts fine when engine is cold and it idles normally. But after I drive it 15-20 min and turn off engine, it idles rough when I start again. If I do nothing, then engine dies after 5 seconds. But if I rev the engine for 5 seconds a few times then idle will settle on normal approx 700-800 RPMs and then be fine.

Engine Air filter is new and no CEL error codes.

I cleaned throttle body and air intake. was not very dirty. Only a little oil in the 2 big pipes.

Outdoor temp is 40-60F.

Any ideas?

Mike