Does Lycoming make any sense?

I just spoke with Lycoming regarding my very high fuel flow. Recently
I've had a problem where I'm getting almost double my normal fuel flow
at idle even with the mixture at the edge of cut-off. I suspected a
servo but called Lycoming. They said I may have a nozzel with a
blockage and the other nozzles are streaming because of it.
Does this make any sense? Could a blockage cause an *INCREASE* in fuel
flow?
I have a JPI fuel transducor wheel that measures fuel flow that has
shown to be very accurate.

-Robert

I'd do a flow test then clean all injectors and do another flow test. Just
have some help and extinguishers around as already mentioned.

Get your hands on 4 baby food jars with lids.
Poke 3 holes in each lid, center large hole for the injector nozzle, 2
outside holes for a piece of stiff wire to fashion into a hanger. (and to
vent air)
Weigh each empty set up, record empty weights.
Insert nozzles into center holes, screw jar onto cover.
Run boost pump after your helpers have been awakened and armed with
extinguishers.
Weigh each jar, compare net fuel weights.
Clean, lather, rinse, repeat.
Jim

Sounds like they didn't understand that you are observing the high fuel flow
on an in-line true flowmeter rather than their pressure-based panel meter.


"Robert M. Gary" wrote in message
ps.com...
I just spoke with Lycoming regarding my very high fuel flow. Recently
I've had a problem where I'm getting almost double my normal fuel flow
at idle even with the mixture at the edge of cut-off. I suspected a
servo but called Lycoming. They said I may have a nozzel with a
blockage and the other nozzles are streaming because of it.
Does this make any sense? Could a blockage cause an *INCREASE* in fuel
flow?
I have a JPI fuel transducor wheel that measures fuel flow that has
shown to be very accurate.

-Robert

Stan Prevost wrote:
Sounds like they didn't understand that you are observing the high fuel flow
on an in-line true flowmeter rather than their pressure-based panel meter.

That's what I thought but I reenforced what I was saying several times.
I really just don't want to send a 600 hr fuel servo for O/H for $2K if
it doesn't need it.

-Robert

Why don't you just have the nozzles cleaned and rule that out?

Robert M. Gary wrote:
Stan Prevost wrote:

Sounds like they didn't understand that you are observing the high fuel flow
on an in-line true flowmeter rather than their pressure-based panel meter.


That's what I thought but I reenforced what I was saying several times.
I really just don't want to send a 600 hr fuel servo for O/H for $2K if
it doesn't need it.

-Robert

Robert M. Gary wrote:
I just spoke with Lycoming regarding my very high fuel flow. Recently
I've had a problem where I'm getting almost double my normal fuel flow
at idle even with the mixture at the edge of cut-off. I suspected a
servo but called Lycoming. They said I may have a nozzel with a
blockage and the other nozzles are streaming because of it.
Does this make any sense? Could a blockage cause an *INCREASE* in fuel
flow?

I remember discussing this when working on my A&P, and promptly forgot
about it after I got out of school. IIRC, it has something to do with
the fuel injection...if one is blocked, the other nozzles pick up the
loss and are sometimes too efficent.

Obviously I can't remember the exact cause, but I've heard the same
exact thing before...blockage can cause an increase in fuel flow.

"Emily" wrote in message Obviously I can't remember the exact cause, but
I've heard the same
exact thing before...blockage can cause an increase in fuel flow.

It causes an increase in the indication on the OEM indicator which in
actuality is a pressure guage, not a flowmeter. Mr. Gary's system uses a
true flowmeter and a clogged injector line should show a decrease in flow.

D.

I don't think so, at least not very much decrease. I think the fuel will
divide among the functioning injector nozzles. This is why the pressure
increases when one is blocked, the fuel is forced through a fewer number of
orifices, causing a greater pressure drop across them.


"Capt.Doug" wrote in message
...
"Emily" wrote in message Obviously I can't remember the exact cause,
but
I've heard the same
exact thing before...blockage can cause an increase in fuel flow.

It causes an increase in the indication on the OEM indicator which in
actuality is a pressure guage, not a flowmeter. Mr. Gary's system uses a
true flowmeter and a clogged injector line should show a decrease in flow.

D.

"Stan Prevost" wrote in message
I don't think so, at least not very much decrease. I think the fuel will
divide among the functioning injector nozzles. This is why the pressure
increases when one is blocked, the fuel is forced through a fewer number
of
orifices, causing a greater pressure drop across them.

If we are talking about the OEM 'flowmeter', how many transducers does it
have? It would need two to measure a pressure drop. It needs only one to
measure the pressure near the spider. If it has only one transducer near the
spider, and a nozzle clogs, the remaining nozzles won't flow enough to
relieve the increased pressure and the result will be an increased 'flow'
indication.

D.

Capt.Doug wrote:
"Stan Prevost" wrote in message
I don't think so, at least not very much decrease. I think the fuel will
divide among the functioning injector nozzles. This is why the pressure
increases when one is blocked, the fuel is forced through a fewer number
of
orifices, causing a greater pressure drop across them.

If we are talking about the OEM 'flowmeter', how many transducers does it
have? It would need two to measure a pressure drop. It needs only one to
measure the pressure near the spider. If it has only one transducer near the
spider, and a nozzle clogs, the remaining nozzles won't flow enough to
relieve the increased pressure and the result will be an increased 'flow'
indication.

The fuel flow measurement does not take into account pressure. Its just
an inline wheel that spins around.

-Robert