I replaced PGM-FI relay. Close examination of pulled unit doesn’t show solder defects or cracking. Bench test of pulled unit shows proper function. Key wiggle does not cause idle shutoff. Stall event caught me by surprise. Instrument lights stayed on. Crank but no start. Flummoxed and did not check for immobilizer green light issues. Got a restart a few minutes later (after fumbling for insurance card and tow number, wouldn’t have worked anyway, no cell service canyon). Afterwards, immobilizer protocols worked correctly (home destination). No MIL light. OBD II scan shows correctly completed readiness, and system performance tests. No data items logged. No codes or pending codes listed. Battery shows full charge at rest (12.7 V). Alternator shows idle 14.7 V measured at battery, and holds value with RPM. First flameout in 20 years since bought new. 265900 miles.

 

OK, look at fuel side now, or emissions.

EGR could stall, and a number of purge valves in the return system.

 

Ignition Control Module, also called Ignitor, can cause that kind of stall, with restart working a few minutes later. How many miles on the distributor?