it is probably shutting down on a low pressure cutout control which is there to do just that if the low pressure drops out of safe range. it is most likely the metering device if you do indeed have a txv type. if the power cap has lost its charge, the system will pump into a vacuum. the technician will need to bypass the low pressure switch to observe whether this is happening. at the same time, the subcooling can be calculated to rule out low freon. if the valve itself is restricting partially, the discharge would rise abnormally as the suction falls abnormally.
the other possibility,as mentioned is a partially or fully restriced liquid line filter drier. this can be determined by allowing the unit to run and looking for a temperature difference across the filter with a strap on or clamp type temperature probe. if it is totally restricted, frost will be evident on the leaving side.
the compressor is pumping fine.