[GOLDROADS]

PART 1 ( fuel pressure )
this ia a stock 5.0 HO . i have 30 psi of fuel at idle . it will increase to 40 psi if i remove the vacuum from the fuel regulator and it does go back to 30 psi when vacuum is replaced . if i close/ pinch of the fuel return from fuel regulator to the tank my fuel pressure does not increase ( i beleive it should ). with the fuel gauge still attached to the fuel line i drive the car and the fuel pressure drops down to 20 psi and lower. this is my problem, under mid to heavy acceloration i get popping / backfire out of the throttle body . i noticed it is only when the fuel pressure is low. by the way this is with a new fuel pump . ( i think i have a defective fuel pump ) . and i beleive the fuel pressure should rise under acceloration. can someone confirm this?
PART 2 ( fuel guage )
the gauge did not ( always read full ) . i got a boneyard sending unit and it tested 12 ohms full and 74 ohms empty ( i beleive this to be the correct specs ). once the tank was back up and filled with gas, the dash gauge reads closer to empty with the more gas i put in. can anyone help here?
IS IT POSIABLE THE TWO HAVE ANYTHING RELATED IN A SHORTING OUT / LOSE OF POWER KIND OF WAY?

[spdjnky_42]

My sending unit did the same thing. I had a bad wiring harness @ rear above tank, But I also replaced the sending unit too as the float may not float!

[GOLDROADS]

thanks i will check the wiring harness .

[EagleAutosports]

Low pressure will cause popping like that, hopefully you'll get it.

[GOLDROADS]

good to know im headin in the right direction, thanks