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Opps, signed off too quick to catch that Mark. Below is what I
wrote to Bob Darrah on the subject. Have not heard back from him yet. I am
surprised that there is any cross-talk in the harness as the GM harness does not
seem to have this problem in the car. The harness in the plane is either
much longer or something else is going on.
Need a few details on harness routing to answer your question.
1. How long is the wiring harness between EC2 and coils?
2. How is the power ground to the coils (A terminals) routed?
(hopefully not in the same harness, if so, there is your problem).
3. Same question as 2. on the power terminals.
4. I would be surprised if this turned out to be the problem but if
coupling between the control lines themselves (C pins) turns out to be the
problem, use either twisted pairs or shielded wires to drive the B & C
lines to each coil. I would lean toward twisted pairs.
5. Are there any other lines routed along with the coil harness
(injector drives, etc)?
Tracy
----- Original Message -----
Sent: Friday, October 13, 2006 4:39
PM
Subject: [FlyRotary] Re: Latest EC2
updates, Installation notes
Tracy,
Before you sign off, can you shed some light on my
previous post concerning cross-firing of the coils and what to do abou
it?
Thanks,
Mark S.
________________________________
From: Rotary motors in
aircraft on behalf of Mark R Steitle
Sent: Mon 10/9/2006 8:31 AM
To:
Rotary motors in aircraft
Subject: [FlyRotary] Re: Latest EC2 updates,
Installation notes
OK, I'll chime in here. After reading
Bob Darrah's post last week where he noticed a big improvement after
separating the leads to his coils I gave it a try on my 20B. It made a
big difference, but was most noticeable in the lower rpm range. I was
only able to separate the wires down near the coils, and then only by a small
amount, but it made a substantial improvement. My question for Tracy is,
can I leave the grounds and +14v wires bundled together and only separate the
trigger leads, or do I need to separate all the wires? Also, if I were
to use 3 individual shielded wires and ground the shields, could I then bundle
the trigger leads together with the rest of the coil
wires?
On a side note, after separating the coil leads,
it took a much leaner mixture to get it to run smooth. Before, the best
it would idle was about 1200rpm, now it will idle nicely at 900 rpm, not that
I want to do that, but it shows that the improvement isn't all in my
head.
Mark S.
________________________________
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Wendell
Voto
Sent: Saturday, October 07, 2006 11:08 PM
To: Rotary motors in
aircraft
Subject: [FlyRotary] Re: Latest EC2 updates, Installation
notes
Tracy,
Would shielded cables be okay to run
close together in a fiberglass
aircraft?
Thanks,
Wendell
----- Original Message -----
From: Tracy Crook <mailto:lors01@msn.com>
To:
Rotary motors in aircraft <mailto:flyrotary@lancaironline.net>
Sent: Wednesday, October 04, 2006 9:31 AM
Subject: [FlyRotary]
Re: Latest EC2 updates, Installation notes
While trouble
shooting Al Gietzen's EC2 engine controller problems, he mentioned that he was
seeing relatively large mixture changes when the alternator was switched
off and the battery voltage went low. The mixture goes leaner with lower
battery voltage because the injectors take longer to open. It was well
within the range of the manual mixture control to correct but it got me to
thinking about adding battery voltage compensation to the EC2. This has
been done and all controllers shipped after 9-20-06 now incorporate this
feature. Not a freebie, but if anyone wants this incorporated into an
earlier EC2 it can be retrofitted.
The other update is a rev
limiter. It was easy to do so I went ahead and added it. I haven't seen this
as a priority because in our application if you make use of it, it means that
you need to be more concerned about the pilot's health than the engine's (the
prop has fallen off the airplane). The default rev limit is 8000
rpm. If you want something different, specify when
ordering. (Also retrofittable)
EC2 / EM2
Installation Note.
This only applies to EC2 engine controller
installations combined with early two-part EM2 engine monitors in canard
aircraft where both units are installed near the engine and have long wiring
harnesses connecting them to the EC2 front panel and EM2 display (a rare
combination that may be unique to Al's airplane). Have been
working with Al for some time searching for the cause of random MAP table and
other EC2 parameter corruption. I am now almost certain that the cause
is noise coupling from the EM2 display harness into the EC2 control panel
harness. The two harnesses were laced together in Al's
installation. He is in the process of separating them now
(sympathies to Al, no picnic). Needless to say at this
point, never run these two harnesses together and separate them as far
as practical. I think Al will have about 4 inches between them
when separated.
Tracy Crook,
RWS
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