fuel presure guage wont read anything(carb)

[91lxvert]

so on my 85, ive got a fuel pressure guage(xrp liquid filled) screwed into a 45 into a AN-T fitting on my fuel feed on my carburator. the first time i started it i had like 5.5 psi, great next time i was showin 3 then 0, car runs great no problems.
so got a new guage started it the 5th for bout 2 min in garage to make sure it worked and it worked, then started it yesterday (2nd time,no driving) after changin jets, fuelpressure was showing 6.5ps for bout 10 min then 4 then 0, so i took the guage back and swapped for an autometer autoguage and it shows 0, zip zilch nada guage dosent even move, all parts are new(fittings,filter,guage,carb,pump).

what is going on? getting tired of this , i cant get it ready for nitrous without haveing a reliable reference for fuel pressure .

anyone got any ideas?
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[rd]

Weird.

I have a fp gage on a tee fitting prior to the tee that splits to the carb and the solenoid feeds. It always reads higher, like 6, at idle, and drops when I
rev it, or after its been driven a few miles, but only to the 4-5 range.

Could be trash in the lines, or air in the gage location, or something odd, like the fuel tank venting system is not working. Try it with the gas cap off. My 82 has some issue with this, but over half tank it runs down the track fine.

Check the fuel pump valves. A carb needs volume delivered, pressure is not that important, relatively. Is the float sticking open, or the solenoid leaking down?

 

[91lxvert]

thier might be trash in the lines but im trying to figure out how, cuz its all new ima pull it apart tonight and look.

also i have a moroso fuel filter that says its only good for about 300hp( just bought it for a quickie, but i think the street avenger already has filters in it for each bowl, not sure) or less, do you think that is causign a lean condition possibly giving me a stumble/stutter while cruising and initial lean on the throttle, any idea?

pump is a mechanical carter(new) and it seems to flow a large volume, found out by accident. im gonna try the gas cap thing and ima check and see if the 45 is bottoming out in the bore restricting flow to the guage.

as for the carb, the floats seem to be operating well, had a hanging needle and seat but remedied that.
other than these problems it runs like a raped ape although
its kinda getting old, 3 guages in a matter of 10 starts and 2 actual drives.