If the fuel you're using has 10% ethanol in it like most pump fuel has these days,that very well could be causing problems with the Holley "blue" pump,as those specific pumps are'nt recommended for use with fuels containing alcohol,and as a result they seem to have corrosion related issues in the cast aluminum lower pump housings.
That often includes problems with gumming up the pumps bypass assembly.
The Holley pump(s) to use with alcohol fuels is either the Holley "black" pump,or their HP line of billet gerotor pumps.
Could also be a faulty gauge too,,,what sorta FP gauge are you using on this???
HTH
Bret P.
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