Today I went out to my plane to fly and found a very odd problem. When
I started the plane after taxiing over the fuel, I could only get it to
run when the mixture was just at the edge of idle cut off. Moving it
even 1/8 forward caused the engine to die right away.
I did some diagnostics. At 1500 RPM I was getting 22lbs of fuel
pressure (normal) and 5GPH in fuel flow (very high). As I moved the
mixture about 1/8 forward that jumped to about 6GPH until the engine
started to die. Running at 2000RPM moving the mixture control to 1/4
caused the engine to totally die.
I run the engine like this for about 20 minutes to make sure it was hot
but no improvement. I even stalled it several times (by moving the
mixture to 1/4 rich) and restarted it. Each restart required 2 seconds
of fuel boost so I don't think it was flooded.
On one restart it ran totally fine, and I was getting about 3.0 GPH at
1500 at 1/4 mixture and about 3.8GPH at 2000 RPM at full rich. So I
shut down again and tried it again and it was having the problem again,
running about 5GPH at 1500 RPM with mixture at the edge of cut-off.

The only thing I can think if is it would be a fuel servo issue. It
seems a little bit intermitant but I seem to be able to make it happen
often enough. Sadly, I'm not at the airport where I normally have
maintenance done and I don't want to fly it now. I've been told to
expect approx $3000 to OH the fuel servo. This is for an IO-360-A3B6
engine.

-Robert