Yep!
Without the second hole you don't operate the 'suction jet pumps' on the ends of the hoses.
Therefore you only get whatever fuel can feed the pump bowl directly.
You'll have to reinvest in a Siemens VDO pump (only trust Siemens VDO).
World Impex used to be a good source, but I can't find it on their website anymore.
Try the forum sponsor, or
World Car Parts seem to have the right one...