Nice job Scott.  Way to go.  That sounds like a lot of work.  Thank you for passing along your discovery.

Kevin
Kevin Stallard
President
Aerial Robotics, Inc.
970.201.1804 (cell)
970.464.4855 (office)




-----Original Message-----
From: Lancair Mailing List <lml@lancaironline.net>
To: lml@lancaironline.net <lml@lancaironline.net>
Sent: Mon Aug 24 20:25:11 2009
Subject: [LML] Fuel Flow Issue Solved

Hello Everyone,

I just thought I would update everyone on my Fuel Flow issue.
 About a month back I asked for advise about a sudden lack of fuel flow.
Where I used to get 20-21gph on Take off I has suddenly getting 12-14gph.
All run ups were normal but when applying full power for takeoff I would not
get enough flow.  When initiating the Electric fuel pump everything turned to
normal.

Well this problem turned into quit the hunt to find the issue.
To make a long story short I had disassembled and reassembled the majority of
the fuel system from the:
Engine driven fuel pump
Throttle control unit
Manifold spider valve
Injectors and lines
gascolator
fuel flow meter
all fuel lines
tank vents
Electric fuel pump

What did it come down to??

A broken O-ring on the inlet side of the Electric Fuel pump fitting.
Air was being sucked into the system.  I finally discovered it by putting a vaccum
on the fuel lines from the engine to the tanks.  When a vaccum could not be held
I traced it to the O-ring.

Four weeks of down time and about 80hrs of work to find the .50 cent problem.
Of course I had to reset all my flows of which I now get 24gph and 22psi on Takeoff.

Now I am still not using my Electric Boost for Take Off.  Should I or should I not???
What is the concensis of people in the know.

Thanks to everyone whom gave me some input.

Scott Keighan
L-IV   IO-550G