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

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.

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

This is just at idle?
Are your manifold pressure and rpm readings in line with each other?
I am thinking about cam shaft wear.

John

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 have a JPI fuel transducor wheel that measures fuel flow that has
shown to be very accurate.

-Robert

The Visitor wrote:
This is just at idle?
Are your manifold pressure and rpm readings in line with each other?
I am thinking about cam shaft wear.

Anytime. However, it is a little bit intermitent. Sometimes it "clears"
itself.
I can't increase throttle w/o increasing mixture but I *MUST* keep the
two perfectly in line, if either gets in front of the other the engine
dies. It really feels like there is no fuel regulation.

-Robert

Robert M. Gary wrote:
The Visitor wrote:
This is just at idle?
Are your manifold pressure and rpm readings in line with each other?
I am thinking about cam shaft wear.

Anytime. However, it is a little bit intermitent. Sometimes it "clears"
itself.

Probably the blockage in a fuel nozzle moving around.

Robert, does it matter whether the boost pump is on or not?


"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