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.
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.
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.
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.
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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