The problem stayed because the accumulator is on the car! It is grouped with the filter and fuel pump at the right rear underneath.
An old, original, accumulator is a valuable maintenance replacement so its worth a shot-gun approach. The real problem is easy to diagnose as the problem is fuel pressure loss over time. The pressure must stay for at least an hour and should stay indefinitely. Any leak can cause the problem the accumulator is just the reservoir. It also just happens to be the most common leak on old systems.
Bosch Master, ASE Master, L1
33 years MB technician