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