Anderson Ed wrote:

Dual pumps configuration.  I have two EFI pumps configured in parallel.
One is automatically controlled by the EFI and the aux is controlled by
a switch on the panel. These pumps have an internal check valve so that
while one is on and the other is off, no fuel back flows thru the
inactive pump.   I take off with both EFI pumps on as well as the boost
pump.  The reason I do it that way is in the event the primary pump
should fail on take off. I normally turn off the aux pump and boost pump
after leaving the pattern and with several thousand feet of altitude.
If the primary pump has failed, I will know that when I turn off the aux
pump. If fuel pressure starts down hill then the aux pump is turned back
on and an immediate return to the airfield is initiated.

As an aside, I think this dialog on fuel systems is great.  Lots of good
ideas being shared.  And given the fact that most engine failures can be
related to fuel starvation due to one reason or another, this forum
provides a great means of getting a sanity check on your fuel system
design before....

Ed Anderson

 
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