1. It sounds as if the EC2 may
not be sensing manifold pressure properly. At low rpm (2000), it sounds
as if it is too rich and you are having to lean it and at higher rpm you
have to enrichen the mixture manually to keep the engine running. As you
know, Normally the EC2 should do this by sensing manifold pressure and
adjusting injector timing - possibly it is not doing that.
2. These are symptoms very
like the ones I had when I left the manifold hoses off the EC2 sensors
(actually, I had plugged them in through the holes in the case but had reversed
the board position in the case - so they were actually stuck under components
on the board)
----- Original Message -----
Sent: Sunday,
April 09, 2006 11:27 AM
Subject: [FlyRotary]
FI mystery
I put about 4 - 5 hours of time on
my engine installation months ago, and had everything pretty much “dialed
in” for proper running from 1000 rpm up to max static rpm (~5200).
Then it sat with no running for about 6 months while I did upholstery, paint
and other stuff in my life. I’ve moved the plane to the airport,
and got it all assembled. Yesterday rolled it out for an engine run-up.
Since the beginning it had always
fired off after a few strokes, and I’d turn off the cold start switch
seconds after it was running. This time I had difficulty in getting it
started. Once I got it running, it would quit immediately when the cold
start switch was turned off. Leaving the cold start “on” it
runs fine above about 2000 rpm with the mixture turned toward lean to about
9:00 o’clock. Reducing rpm lower it wants to die. As I increase rpm
above 2000 I need to rotate mixture knob significantly toward to richer to keep
things smooth.
Fuel pressure, MAP, ignition, etc.
all are normal. When I get the mixture knob adjusted it is smooth, so
injectors are working on all three rotors. I didn’t take it above
the staging point so it is running on one set of injectors. Haven’t
had a chance yet to look at the mixture map on the EM2, and won’t get
back to the airport until Monday.
I’m a bit baffled on what
could have changed since last operation and what to check. Anybody have
any similar experience? Ideas?
Al