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

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" <N7093v@> wrote in message
news:1161377927.635968.40220@m7g2000cwm. 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
>

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
>

If I remember my "mechanical fuel injection 101" there is a "relief
port" of sorts somewhere. The pump delivers enough for the injectors
and then some. The "relief port" orifice bleeds off the excess and
returns it to the tank or the input side of the pump. Different size
ports changes the fuel delivery for different size engines. If it gets
clogged I would think the pump would deliver way too much fuel. Your
system, however, may not be like that. Just a guess.

Jim


On Oct 20, 4:58 pm, "Robert M. Gary" <N70...@> 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, does it matter whether the boost pump is on or not?


"Robert M. Gary" <N7093v@> wrote in message
news:1161377927.635968.40220@m7g2000cwm. 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
>

That is for a different kind of injection system, used by Continental but
not by Lycoming. Lycoming uses RSA which does not have a return-to-tank.

At least it used to be that way.


"jim" <jfleisc@> wrote in message
news:1161386366.903714.60180@e3g2000cwe. ps.com...
> If I remember my "mechanical fuel injection 101" there is a "relief
> port" of sorts somewhere. The pump delivers enough for the injectors
> and then some. The "relief port" orifice bleeds off the excess and
> returns it to the tank or the input side of the pump. Different size
> ports changes the fuel delivery for different size engines. If it gets
> clogged I would think the pump would deliver way too much fuel. Your
> system, however, may not be like that. Just a guess.
>
> Jim
>
>
> On Oct 20, 4:58 pm, "Robert M. Gary" <N70...@> 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
>

Stan Prevost wrote:
> Robert, does it matter whether the boost pump is on or not?

No, pressure holds solid at 22lbs.

-Robert