In article ,
kontiki wrote:

Ben Jackson wrote:
I have a Comanche with mains and auxes, but no tips. The first thing
I'd check in your setup is the tip tank pumps. My understanding is that
when you have tip tanks, you fly the auxes down, then pump in from the
tip tanks. Perhaps some misoperation of those pumps could affect your
fuel flow.

Also, try operating the fuel drain in the various settings. Do you see
bubbles or excessive flow from the drain when the auxes are selected?

Comanche tip tanks don't use pumps. They can be used anytime while in
cruise (not for t/o or landing). I think his problem is either a clogged
tank vent (one time a mud dauber made a nest in my right tip vent) or
possible fuel line blockage. It could be an air leak in the line as
well, but that would generally cause some leakage that you might notice.

How about a little water in the sump and ice crystals blocking the
finger screens in the tanks?