91 accord, started then died a few minutes later, no spark
 

Timing belt is ok, main relay is ok.

There is some maroonish powder under the distributor cap. So it could
be the distributor, coil, and/or the ignitor?

Spark plugs were way overdue for replacement and the gap was like .070!
Installed new plugs last night gapped at .040. New cap and rotor too.

How can i test the coil? What does the poweder/dust signify?
thanks