One thing about testing this theory with a small reservoir of fuel:

The Digijet system (like L-Jet) recirculates the fuel at a fairly high
volume (more than needed for the engine's combustion mix anyway) so a
reservoir volume of fuel nearer a gallon would be needed.  Then, the
consumption would need to be measured over a given amount of time without
actually running out of gas.  Otherwise the fuel pump could be damaged;
the pump is lubed and cooled by the very fuel it pumps.  Dry-testing the
pumps is a big no-no. :)

Gregory Smith
Olympia, WA
'84 Vanagon