I had similar problems... twice... with my 88 300CE. First time eventually it would not restart & needed a tow. Dealer changed the FPR. About 3 years later started having the same problem. By then I had figured out to drop it into neutral restart and keep going. Took it to the dealer and told him about it. They checked & replaced ignition wires & rotor. Maybe plugs too, I can't recall from memory. Problem solved. That was five or six years ago. Never had a repeat. Knock on wood.

My two cents JD is do the simple & cheap things first. Wires & rotor are cheaper than the FPR.
Good luck. Losing propulsion is never good whether on the high seas or on the road.