500 SEC Dies

HELP, my 1985 500 SEC with only 187,000 miles has suddenly developed a major problem. At times (no pattern, not telling, just whenever) the engine will just die. It has happened at idle, at low speed and at full highway speed. There is no indication in the car that the engine has died, no indicator lamps, tach remains up, all is well, but no combustion. Switch the car off, coast, or wait 30 to 45 seconds, and the unit will restart, sometimes on the first but seldom more than the third try. All is functional,operation is fine till the event occurs again. Any ideas?, This is a killer in Atlanta traffic. I am virtually certain that it is a fuel problem, but what, pump makes good pressure, and is only 12 months old, so is the filter.

HELP,
Mark