Yes it has a spark when warm.

Hi Frank, I'm beginning to get the picture.

High pressure signal from WUR leans out the FD to the point that the engine stalls and will hardly hardly restart.

(And this is despite the mixture, I would say, being pretty rich at cold idle. Certainly smells like it's dumping gas in there.)

What do you suggest I do next? As I mentioned earlier the WUR is a recent rebuild from H&R in Long Island.

I guess it should go back to him, or can I look to another solution?

Best Ed