I was just re-reading your symptoms again and have one more thing to offer as a possible cause, although this should have thrown an appropriate code, and that is the ignition sensor. It could be partially failing and give you that "engine switching off like a light switch" condition and then starting again later like nothing was wrong thing.
I see for the I4, it's in the distributor and is not cheap!!!. for the V6 without a distributor, it's a bit cheaper, not sure where it is hidden. Don't know how this applies to your engine, but if after all you have done the problem persists, it may be worth a try.
Had this random dying on a '91 plymouth acclaim, turned out to be the hall effect switch in the ditributor (ignition sensor) and it would just die from time to time, but it did store the code properly and replayed it via flashing lights thru the dashboard. Last time it did that I was on the freeway and it only gave me one shot at the brakes before losing vaccuum boost - it did not want to stop after that!!!
I see for the I4, it's in the distributor and is not cheap!!!. for the V6 without a distributor, it's a bit cheaper, not sure where it is hidden. Don't know how this applies to your engine, but if after all you have done the problem persists, it may be worth a try.
Had this random dying on a '91 plymouth acclaim, turned out to be the hall effect switch in the ditributor (ignition sensor) and it would just die from time to time, but it did store the code properly and replayed it via flashing lights thru the dashboard. Last time it did that I was on the freeway and it only gave me one shot at the brakes before losing vaccuum boost - it did not want to stop after that!!!