This is driving me crazy.

symptoms-

ran real low on gas (just before symptoms)
drove for four hours on freeway.
shut down,
on start, it stumbled, misfired, had no throttle response.

Today, it will not idle at cold start.
If I hold 2000 rpm and warm it up, it will idle.

After warmed up, it still misses but it will catch and
have full power for a few seconds, then goes back to running
as if on three cylinders, low power. not much throttle response.

Is this a temp sensor problem?
What are AMM symptoms?
This feels like a bad intake leak, but the fact that
it catches and runs fine for a few seconds feels like
an electrical problem.

Where do I start?