Mailing List lml@lancaironline.net Message #42012
From: John Schroeder <jschroeder@perigee.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: IO-550 fuel injection
Date: Thu, 10 May 2007 11:25:27 -0400
To: <lml@lancaironline.net>
Rick -

Remind me to hire you for any kind of troubleshooting on our airplane. Excellent and thoughtful listing of hypotheses/checklist items for Eugene, and all of us to look into.

Cheers,

John




On Thu, 10 May 2007 09:51:27 -0400, rtitsworth <rtitsworth@mindspring.com> wrote:

Eugene,

First a couple silly thoughts (which don't seem to apply since it
mysteriously now works again), but seemed like potential learning
opportunities (for me anyway).

1. Does anyone know the failure modes of the electric boost pump?  I
know/believe it is a free flow design but if it's impeller/diaphragm (???)
fails "could' it cause a restriction?

1b. How does the Dukes pump work?  Anyone have an exploded view diagram for
future reference?

2. What is the behavior of a plugged (or partially plugged) gas collator?
Is it a potential restriction?

3. Is your collator drain easily accessible?  Do you drain/sump it every
flight?  Ever get any H20 from it?  Do you disassemble/inspect it at annual
CI?


A couple other questions;

4. Does your wing tip fuel vent line make a vertical turn before going to
the tank (so water would have to go uphill).

5. Were your fuel tanks both full (maximum gravitational head pressure)?  If
not, any chance for similar high h20 condensation on the inside - partially
restricting the gas collator?

6. What was the approx temp on the ground?  (I'm assuming it wasn't too hot
yet at 8:30am)  Any idea of the temp enroute?  (I'm assuming no bizarre
atmospheric phenomenon, and 8500 doesn't seem all that high anyway from a
fuel vaporization standpoint).  Also assuming normal 100LL fuel.

7. What were your approximate cruise power settings and fuel flow at the
time (assuming 25"ish MP, 2400/2500'ish RPM and less than 20 GHP?

8. Do you have the original ES fuel-line set-up (sharp 90' fittings at the
tanks, flex line to the fuselage wall, sharp 90' bulkhead fittings, 3/8"
hard line to the selector (Andair), more sharp 90' fittings at the selector,
3/8" line to the boost pump (Dukes) and to the collator (old Lancair style
vs Andair collator).

9. Where is you boost pump located and how is it oriented? (assuming it's in
the cabin, on the lower firewall, oriented vertically)

10. When the pressure/flow when to zero, did the engine stumble/quit?
(trying to rule out any sort of engine monitor/gauge error)

11. Assuming nothing else unique/abnormal about the flight (gross weight,
other???)

12. Really bizarre thought... Could a restriction in the engine fuel pump
vapor return line cause it to stop flowing and leave the engine pump
cavitating (not able to prime)?   Does anyone know approx how much
fuel/vapor cycles back through that circuit (under normal conditions)?

Rick


-----Original Message-----
From: On Behalf Of glong2
Subject: [LML] Re: IO-550 fuel injection

I would like to share an experience I had with what I believe is a fuel line
vent problem on my ES.



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