If you just now hooked up the fuel gauge.. it may take awhile for the pressure reading to stabilize. Did you purge the line from the bowl to the gauge ?
Yul need to purge (bleed) the tubing line From the bowl, To the gauge.. at the gauge. Air in that line will not give you True fuel pressure. (air compresses differently than liquid ?)
Is the gauge in the Cab ? If so, you [should] use an [Isolator]...
Joe
On edit: Try driving it for a day or two after you bleed the gauge line.. you may have some air in the fuel system.. from the QD inlet delete ?
