Hi All:

If we're talking about the Facet "beer can" style pump, the pump can be left on
indefinitely. (Have taken one apart. Nothing to them.) There's no heat
limitation. Depending on your plumbing (parallel or series), it might affect
your mixture very slightly in flight. (Carburetor.)

The right tank problem could be due to deteriorating fuel / vent lines in the
wing. Light Plane Maintenance did an article on pulling the tanks and
replacing these hoses. They're rubber hoses with a life limit and the usual
breakdown deterioration. You're looking at a tedious job. (If you can get a
337, I'd replace with a longer life hose. Maybe an AQP style.)

Aircraft Spruce sells Facet replacement pumps.

At different power settings/attitudes, right? Fuel pressure gets awfully
low on mine if I turn off the electric pump in a full power/rich power-on
stall attitude... probably 1psi. As I said befo marginal.

Cory's problem is probably endemic to the Piper vent system. I suspect, during
the stall attitude, you're pulling a slight vacuum on the vents.

On our Glasair, we had similar low pressures in climb attitude. Turns out the
vents didn't protrude far enough below the wing. I extended the vent tubes
another inch and a half, and that solved the low pressure on climb out problem.

Hope this helps,

Mike Palmer
Excellence in Ergonomics