Check the gascolator for a leak !
Had a similar problem on my Archer II.
In climb the fuel pressure gage fell back to midway between the red and the
center point of the green arc.
After leveling off the indicated pressure slowly came up.
With the electric pump on the variation was significantly less or stable at
higher indicated pressure.
I foolishly flew the bird halfway across the country like this.
Back at home, my AP found the gascolator top seal was unseated and leaking.
New seal fixed the problem - now have normal indicated fuel pressure with or
without the electric pump.
Normal for this and our club's Archer is needle in the center of the green.
Don't accept this varying pressure something is adrift.

Good Luck,

Roy



"PaulH" wrote in message
om...
MC wrote in message
...
Does your fuel-pressure gauge fluctuate noticibly ?

Mine vibrates at about a 3Hz rate between the
middle and bottom of the green-band.
Engine runs fine...

Turning-on the electic pump reduces the amplitude of
the swing and stablizes it at around mid gauge.

Is this 'normal' ??

My 69 model does not fluctuate. Air in the line?