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Ed,
Some thaughts on your vaccuum pump.
You can stand next to the engine while idling with
the cowling off and do some checking. You can disconnect lines and feel
for suction (or test with another gage). Also you can hear better or
even put your hands on the suspect parts and feel for any vibrations that
may accompany the squealing. Next, take the pump apart.
For your boost pump you have two problems.
The new pump doesn't work. Mine has a sticker
on it for flow direction but it's wires don't have any
polarity.
When I had a rough running problem, I did a
lot of rework on the fuel system. (even though the problem turned out to be
ignition related.)
I did a gascolator drain test like you describe and
timed the result. At gravity feed there was only about five gallons per
minute flow. This is only about one quarter of the engine demand at full
power and tells us that there is a definite suction in the lines between
the tank and first pump. (When the boost pump is off, this suction is present in
the whole system up to the engine driven pump.)
I have no filter on this line either. I
suggest you remove the filter or at least put it downstream from the
dukes.
If you are going to put it downstream, be sure it
can handle the pump's pressure.
For this to apply to your priming difficulty, you
would have had to have a very large air leak and a lot of resistance in the
filter.
I don't expect that moving the pump lower would
help at all but check that all the lines from the tank to the pump slope
downward.
I would track down that fuel smell if I were
you. Look for any trace of blue staining. I had to repair a small
leak in the header tank once.
Mark Ravinski
N360KB 1304 hrs.
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