if it's of any help ..
re. the engine bay :
looking from the front of the car .. at the h.p.fuel-pump ..
low pressure feed to pump .. be on left .. rubber hose type
low pressure return-to-tank .. be at right .. rubber hose type .. [ nearer to the h.p.pump regulator ]
or ..
the fuel return from the injectors .. connects to same metal pipe
as the 'return' from the h.p.pump ..
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trace the lines