Emergency

vibration. The engine still sounded good and was still making 2500 rpm,
but
the prop was probably in flat pitch to do it. I tried the electric fuel
pump: no joy. I glanced at the JPI engine analyzer and saw that all four
cylinders showed roughly even EGTs. All this took much less than a minute;
maybe only 30 seconds.
Finally, I pulled the carb heat. Within a few seconds I felt a surge of
power and we began to climb. I don't know for sure what a death row inmate
feels like when the governor calls at the last minute, but I'm guessing it
feels something like that.

I thought with a fixed speed prop, the clues for carb ice were reduced MP
and possibly decreased EGTs from a richer fuel burn? Where as on a fixed
pitch prop, rpm drop was the first clue.
Is this not correct?

Yes.