Not sure if this'll help or not, but Honda temp sensors frequently "die cold." Here's what I mean: When the engine's cold, the temp sensor puts out about a half a volt. As the engine warms up, the sensor's output voltage increases... up to about 5V for a fully warmed up engine. Then, for some mysterious reason, the sensor will die, putting out a half a volt again, even though the engine is fully warmed up.

You can drive around like that and not notice it. But when you shut off the car and try to RE-start it, the ECU (thinking the engine is "cold") will flood the warmed-up engine -- which it SHOULD do if the engine's cold.

When the engine cools down (30 minutes?) it'll start okay, cause now it WANTS the extra fuel.

Does this sound like your symptoms?