daveg

I installed an Autometer F / P gauge & a Holly Blue transfer pump, set at 8 psi, was happy with the results. Now ( 2 months later ) the gauge is fluctuating rapidly between 6 to 9 psi... what's up with that ?

thanks, Sven.

I should mention that the gauge is mechanical ( $ 60 ) & I tapped into the high pressure port on the top of the filter housing & used 1/4 in. hydraulic line.

crobtex

Fill in your sig so we'll know what your driving........

TDX

my truck also has the same uneven fuel pressure. after i put on the aux. pump it was steady at 23 psi but after about two months it started bouncing all the time about 1 to 2.5 psi
that was a year ago and things are still okay , but still bouncing

infidel

Brewster, I'm originally from Chelan.

What you are most likely seeing is pulsations from the VP. Adding a gauge snubber or better yet a needle valve almost closed should eliminate the gauge bounce.

daveg

Solved the bouncing needle issue on my '99 by routing the gauge line to have a loop above the level of the gauge & the fuel filter housing ( point of connection ) & draining the fuel in the line at the gauge while the pump was off. The line has trapped air between the fuel level & the gauge & dampens the pressure pulsations. If the needle fluctuations re-occur, the air has leaked out somewhere, but draining the fuel out again will make room for more air.