Ok so I installed a B&M fuel gauge last night. At idle, without touching anything it shows 28 psi fuel pressure. When I disconnect the regulator from the intake manifold it shows arond 38-42 psi. Is that normal or is it way too low? BTW this is on a B16A

 

yes, most stock fuel return systems use a 1:1 fpr. the lower pressure at idle is cause by manifold vacuum. our engines run 18-22in. Hg vacuum which is clsoe to 10psi.