If I understand your observations…embedded
below.
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of sboese
Sent: Monday, July 13, 2009 6:24
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] cold switch
and injector backup mode
This weekend I had a chance to make some observations
concerning the previous discussion on the use of the cold switch and the
injector backup mode on my EC2 used with a 13B.
When idling, turning on the cold switch results in all four
injectors delivering fuel at the pulse width that was used by the primary
injectors before the cold switch was turned on.
Below staging manifold pressure, cold
start doubles fuel flow by turning on both sets of injectors, effectively
canceling staging.
When idling, turning on the cold switch results in the
staging data bit changing from indicating operation at MAP below the staging
threshold to operation above the staging threshold even though the MAP is very
low.
When staging is canceled by the cold start
switch, it is indicated on the EM-2
With the cold switch on, gradually increasing MAP results in
a gradually increasing injector pulse width from idle to full throttle with no
discontinuity when the staging threshold is crossed.
Cold start has no effect on the fuel
delivery after the normal staging point has been reached.
Turning off the power to either the primary or secondary
injectors has no effect on the pulse width applied to the injectors or the
status of the staging data bit.
The injector disable does not work above
the staging point. If you kill one set above the staging manifold
pressure, you will just be running on one set at the normal pulse width. This
will result in only half power or less available anywhere above the staging
point manifold pressure.
This does not sound like the way I had
previously understood the injector disable to work. Are you sure you have
it wired correctly?
Based on the above observations, it appears that the EC2
does not need to know whether or not power is being sent to the
injectors. Regardless of the MAP at the time, turning on the cold switch
results in the EC2 operating with all four injectors as if the MAP was above
the staging threshold but with a pulse width appropriate for only two injectors
being used.
My statements below concerning the cold switch position
appear to be in error. The position of the Cold Switch is not one of the
things contained in the data log captured from the EC2 so that piece of data
was from my memory which is poor at best. Sorry Bob.
I probably should have maintained the “Avoid
reading….” subject line.
Steve Boese
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From:
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Steven Boese <sboese@uwyo.edu>
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Subject:
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RE: [FlyRotary] Re: Below staging
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Date:
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Mon, 6 Jul 2009 00:24:28 -0600
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To:
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"'Rotary motors
in aircraft'" <flyrotary@lancaironline.net>
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Bob,
In contrast to when the primary injector power
is off, when the
secondary injectors are turned off and the cold
switch on, the EC2
indicates staging is taking place normally at
the staging threshold, in
my case at about 20 inches MAP. The engine
doesn't go lean after
staging is indicated, however. When idling with
the secondary injectors
turned off and the cold switch on, the EC2
indicates no staging has
taken place. Of course, what the EC2's staging
data bit is telling the
outside world and what The EC2 is actually doing
may be two different
things.
Steve Boese
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