John,
Sounds like you're racking up the hours.

If I were you, I think that I would switch the fuel pumps around to make
sure that was the problem.  I suspect that it may be something else.

I don't know your fuel set up, but if the pumps pull from different tanks,
ten maybe you have a blockage somewhere.
Also the regulator would be a candidate as well.  The pumps put out much
higher pressure than the 38 or so lbs of regulated fuel pressure.  Double
check the MAP pressure line connected to the regulator to make sure that it
isn't leaking.

Steve Brooks



-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of John Slade
Sent: Sunday, March 20, 2005 10:55 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Fuel pump question


Fellow rotary people;

I did another 4 hours over the weekend. Everything was pretty much plain
sailing.

I'm having a problem with one of my fuel pumps and was wondering if anyone
else has seen anything similar. The pump seems to work ok for 10 minutes or
so, then the pressure drops off maybe 5 PSI. If I leave it the mixture drops
off the scale and the engine starts to falter. As soon as I switch to the
right pump the pressure comes back up and the mixture comes back to the
middle. Leave it for another 10 minutes and it'll be ok for a while, then
back to the same scenario. I checked the pump after a flight and it was
quite cool. Check it in the hangar and it puts out exactly the same as the
other pump. I cleaned the filters quite recently and there was no sign of
blockage.

I'm guessing I need a new pump.
John (29.2hrs. Wish I could have an autotune chip without being grounded for
a week)


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