Also I wonder if you have something floating in the tank that is sometime blocking the return. I believe that is also happening to me. If I cruse long for a period of time I sometimes see my float starting to raise and if I do nothing it will eventually overflow from the vent. If I wiggle the wings or nose some to slosh the fuel around a bit the float starts down again. I really need to fix that.
Kevin1 --- In [email protected], "kgassert" <kgass...@...> wrote: > > When this is happing is the sight gage rising indicating that the > fuel is indeed not returning as needed? If so and if there is good > return lines and no leaks as you indicate then the only place for it > to come out would be the vent hole. So again if the returns are open > and no leaks are there then the pump would have to be pumping too > much and overwhelming the returns. I take it from this discussion > that you don't have an engine driven pump, only the electric? > > Kevin1 > > --- In [email protected], "Bert" <stkbull@> wrote: > > > > Thanks everyone for your input. Thus far, we have not solved the > > problem but we have numerous good leads. Responses to the > individual > > who spoke up follows: > > > > Thanks Dan C > > - I have flown for four years now, including many long cross > country > > trips using the electric fuel pump. Only turning it off when the > red > > light comes on indicating a dry line (empty wing tanks). A > condition > > that has always occurred at about 2:45 to 3 hours of flight. > > > > > > Thanks John Cooper > > - Having filled the tank and tested it (and all the lines) under > > pressure, we are somewhat mystified. There do not appear to be > any > > leaks, holes, cracks, etc in the systems plumbing. > > - The inability to replicate the event during static ground tests, > > mystifies us as well. > > > > > > > > > > Thanks Bill N1659Z > > - The cap (and sight tube) are brand new. The old cap (with an > > unprotected wire protrusion sight gauge) had a thin very old > gasket. > > The new gasket is surely making a better seal. > > > > > > Thanks Syd > > - The black rubber gasket is old and is a possible culprit. > > - Yes we have verified the return line is clear. > > - I'll have my A&P check the `restrictor'. > > > > > > > > Thanks - W. R. Bayne > > -Yes the return line appears to go to the right wing tank (it is > > clear, unobstructed) > > -Yes the vents on all three tanks are clear > > -I am looking up the old records for fuel system modifications as > you > > suggest. I have been flying this plane regularly for four years > yet > > never experiencing this problem (except for a frequent fuel > smell). > > Changes made over a decade or longer in the past should not be > first > > evidencing a problem now. > > -Your idea about the "seal" being the culprit, seems worth > pursuing. > > The seal looks good, but is VERY old. I do know fuel was filled > > above the the neck joining point during our test yesterday. > > -I don't know what PSI the A&P used. > > > > > > Thanks everyone. > > > > Bert Hampton > > >
