As stated earlier, have turned pump off momentarily and back on, the
engine restarted immediately. For longer duration engine off  glide
testing, should both the injectors also be turned off? My concern is that
without fuel in the rail, engine windmilling , the control will probably
continue firing the plugs and injectors. What should be disabled beyond
turning fuel off ?? ----------

I think I'd choose to turn off the injectors, and leave the pump on, or turn
it on at intervals.  Leaving the pump off for an extended period could allow
the pressure to bleed off, and with no flow in the hot environment, could
result in vapor forming in the line or fuel rail.  This should clear fairly
quickly when the pump is turned back on; but even short delay could cause an
adrenalin injection and rapid heart rate.

Al