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Ed,
I was not clear in my description of when the
problem seems to be occuring. So to clarify:
In my normal tuning of the EC2 I never mess
with the B controller. And have never noted a problem with corruption of EC2
data. When I began flight testing back in February thats when the problem began
to occur. After 3 instances I stopped flying.
I decided it was about time to resume flight
test last weekend after 4 months of mods and ground running without any
problems. On saturday I flipped to the B controller just to see if it was
OK and the engine died. This was not immediately preceeding a planned
flight and I did not perform an ignition check. Over the course of the weekend I
had a total of 4 cases of corrupt data. Three times there was an undefined
problem on B that prevented the engine from running and one case where the A
staging point got corrupted. The ONLY difference between these 4 cases of
failure and the previous 4 months of failure free testing was the selection of
the B controller. I never tested the ignition.
These 4 failures occured over the course of
approximately 25 engine starts and a total run time of about 2.5 hours this past
weekend. For each engine start I toggled back and forth between A and B multiple
times at various RPM settings. I estimate around 100 operations of the A/B
switch resulting in 4 failures. The definition of intermittent.
Does this clarify? BTW, I am going to take your
advice and add a .01uf cap on the A/B input. What have I got to lose at this
point?
Thanks,
Mike
----- Original Message -----
Sent: Friday, July 03, 2009 8:39 PM
Subject: [FlyRotary] Ignition Check?? Re:
frustrating couple of days
Mike,
I could not help but
wonder that when you were unsuccessfully attempting to replicate you B
controller problem by switching back and forth - did you also try your
ignition check while in B? You mentioned that you normally made an
ignition check with controller B on in preparation for flight. However,
you did not indicate that you were making such a check when you were trying to
duplicate the problem.
IF you did not, then
I would suggest that you again try to duplicate the problem by switching from
A to B, but include the ignition check while in B. Do it a few times and
see whether or not B gets corrupted.
Ed
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mike Wills
Sent: Friday, July 03, 2009 10:59
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: frustrating
couple of days
My staging point is set at 18"
which ends up being around 3300RPM. So far I still havent been able to prove
for certain that the corruption is linked to switching A > B, much less
determine that it only happens above or below the staging
point.
All 4 of my injectors are the same
- checked them all with an ohmmeter. They are all of the type that does not
require an external resistor.
----- Original Message -----
Sent: Friday,
July 03, 2009 9:13 AM
Subject:
[FlyRotary] Re: frustrating couple of
days
Mike,
Is 3000 rpm above
your staging point? If the corruption of the controller only happens
when changing from A to B above the staging point, check to see if one or
both secondary injectors have lower resistance than
specified.
Steve
Boese
-----Original
Message-----
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mike Wills
Sent: Friday, July 03, 2009 9:50 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: frustrating
couple of days
Thanks for the offer and the
input. Swapping my EC into your plane would be a desperation last move due
to all of the hassles involved. And as you say would not necessarily prove
anything.
I said it happens when I'm
preparing to fly, but that isnt entirely accurate. It would be more accurate
to say that in the past it has happened only when I have switched
to the back-up controller which usually occurs in prep for flight. This
past weekend I had fired it up and taxied down to EAA for lunch. After lunch
I taxied back to my hangar and prior to shutting down I ran the engine up to
about 3000 RPM and switched to the B controller. The engine died and I had
to copy the A program to B to get it to run on B. Switching to B
was the only pre takeoff checklist item I
performed.
I think about the only thing you
hit on here that might be related is heat. But hard to say without more
instances of failure and a way to link cause and effect. On saturday
when the engine quit on B the engine was completely cowled. On sunday when I
had the second instance of an engine quitting on B, the upper cowl was off
but the lower was on. When the staging point was lost the upper was
off, lower on. Yesterday when the engine quit on the first attempt at
switching to B the engine was completely uncowled. Maybe I'll run it up a
few more times today uncowled and if it works OK, try putting the cowl back on and see if I can
induce failure. Doesnt seem likely though that anything under cowl could
cause this sort of problem.
This may all have to wait until
Tracy weighs
in with his opinion. I'm not inclined to make drastic changes until I hear
from him.
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