Finding leaks in the suction section of the fuel system

[cossitt.alan]

A reoccurring problem I've had with my airplane is fuel starvation at low
RPMs. When taxiing I've had my engine just stop due to fuel starvation. I'm
suspicious I've either installed my Mikuni fuel pump in a less-than-optimal
position, or that I have a leak or restriction in the suction part of my
fuel system. My work-around is to turn on my electric fuel pump when
taxiing or landing. I'm moving toward the conclusion that perhaps I should
use my electric fuel pump as my primary fuel supply and consider the
mechanical pump as my backup. Mark says electric fuel pumps run 500 or more
hours without failure and that is several years of flying for me.

During my annual, I'm going to look hard at my fuel system. One question I
have is how do I check for leaks between the pump and the tank (suction
leaks)?

Alan

[earthstaraircraft]

Hi Allen
It’s not hard to turn on the auxiliary, temporary, fuel pump if you here the engine slowing down wile taxiing.
But if you really on your electric pump all the time, it will fail and you won’t know it till you really need it.
So be sparing with it.
And fix any air leaks in the suction side of the fuel system.

Happy Flying,
Mark

Sent from our iPhone

[cossitt.alan]

Thanks, Mark. Do you have any suggestions on how to find those air leaks?
That is what I'm struggling with right now. My assumption is that air will
leak much easier than gas (so looking for gas leaks may not be sufficient).
I could pressurize the host (first disconnecting it from the pump) and use
soapy water at each connection...

Any thoughts? I'm sure you've done this a few times ;)

-Alan