My bad! I meant FCU not PT Governor. Although, the PT governor was overhauled as part of the diagnosis showed it was out of limits although not due for OH by time.I'll edit the OP.
BTW it's a Bendix system.
FCU has been swapped for another one, as has engine driven fuel pump. Issue still persists. There is NO evidence of external leakage of fuel, in flight or during the start process.
To bleed it, the nut on the FCU end of the line from the fuel pump has to be undone, the electric fuel pumps switched on until fuel runs out (being careful not to let fuel flow into the Starter/generator), then the nut is done back up. All this of course with the fuel line into the burner can removed and wrapped up in a plastic bag.