The MAS is a larger OVP. It is just a power supply relay with spike protection. Sort of like a UPS for your PC.
The answer to your basic question depends on the natuer of your problem. If you have a problem cold the accumulator is not involved. If your problem is hot restart it could be. A hot restart problem would occur between 15minutes and an hour after stopping (with hot motor). The problem in these instances is a vapor locking condition due to fuel boiling when it isn't under pressure.
The fuel pressure builds almost instantly so the pressure doesn't have to last any longer than that which is necessary to increase the boiling point during the hottest period.
If on the other hand your problem is cold it is less likely to be fuel delivery related as fuel pumps that eventually work (at 6+amps each), work best when cold. More likely in this event is the lack of fuel enrichment (if this problem is fuel related and not ignition) for cold starting and cold running. This is accomplished by the EHA current being higher when cold. In cars with OVPs the way they affect cold starting is by shutting down the KE controller thus there is no enrichment at all.
Bosch Master, ASE Master, L1
33 years MB technician