The pilot of an arriving aircraft requested that emergency services be placed on standby, as his aircraft was experiencing engine surging in the right engine and he did not expect to make a normal approach. A short time later the aircraft made an uneventful landing and taxied to the general aviation terminal accompanied by a fire tender. An investigation was subsequently carried out by a maintenance organisation with no fault found. This included draining and testing 20 litres of fuel from both main tanks. No contamination problem that may have attributed to the engine surging could be identified. After engine ground runs to verify operations were within limits, the aircraft was returned to service.