I could use a little help on this problem. I apologize for
the length.
My engine recently started to show signs of fuel starvation. Cutting
out above about 3K rpm. It would just seem to go from 3K to idle. I
was running on my primary fuel pump, so I turned on the secondary and the
engine would start to run normally. (Not like gangbusters, but
NORMALLY. My max static rpm has been about 52-5300 rpm and I have felt
that it was not getting enough fuel to run up to my goal of 6K static)
I decided that I had a filter plugged, and fearing the gasohol
that they are now selling all over Florida, I opened up my Gascolator. It
was ok. I found a couple of wisps of white fibers. Could be
fiberglass dust, could be spider webs, something like that. I
don’t think that I have had any gasohol in the plane, but it is probably
possible. But the Gascolator was fine.
I then opened up the JEGS inline filter on the primary pump and the
element was covered with a black sludge. It seemed to be almost
completely blocked. This stuff looked like maybe it could have come from
the inside of the SS braided hose.
I checked the secondary pumps filter and it was fine. I have not
used this secondary pump except on rare occasions to check for pressure
changes, leaks, etc..
But for that matter, I have only run three 5 gal cans of gas in the
plane totally. One 5 gal can in each wing, then another in the right
side, and I am now pulling out of the left tank which has the fourth 5 gal in
it.
So, like I said, I at first thought that it was a rubber residue from
when I installed the hose ends on the Aeroquip hoses because it sort of looked
like that. Then as I drove home, I remembered that there was none of this
stuff in the Gascolator. (I think that some should have made it there as
there is one -8 hose in front of the Gascolator) There is only about a
foot of -8 hose in front of the fuel pumps after the Gascolator, so now I am
thinking that maybe it came from the fuel pump.
Is there anything inside the pump that could cause a black sludge if it
started to crap out? What would I look for to check if the pump is out or
going out. Has anyone else had any similar problem? I recently
heard a squealing sound from the area of the pumps, but at the time I thought
that it was bubbles going through the pump. I was close to empty on the
right tank and thought that it was sucking air. I switched tanks and the
sound went away.
I have not yet checked my injectors. Two reasons: I
have no idea of how to do it and would not know what to look for. Is the
40 micron screen fine enough to keep anything from getting plugged up in the
injectors? If not, what do I look for, and where?
I would greatly appreciate some input as to your thoughts on
this. How would you proceed?
My fuel system goes: Finger strainer in tank, ½ inch aluminum line to
Andair dual valve (switches both supply and return to same tank), Aeroquip -8
SS braided line, boost pump, Aeroquip -8 SS braided line, Andair Gascolator,
Aeroquip -8 SS braided line about one foot to splitter to two fuel pumps,
(these are the pumps that Tracy sells), each pump is followed by a JEGS billet
in line fuel filter with a stainless 40 micron element. Then a splitter
to bring them back together to Aeroquip -6 SS braided line, primary injector
rail, Aeroquip -6 SS braided line, secondary injector rail, Aeroquip -6 SS
braided line, Aeromotive fuel pressure regulator, Aeroquip -4 SS braided line
to the valve and back to the tank. The tanks are fiberglass with
ProSeal. This is a Lancair Legacy, Renesis engine.
Thanks for the help.
Bill B