Message-ID: <007701c42d91$30be6b30$0000a398@Carol>
From: "sqpilot@earthlink" <sqpilot@earthlink.net>
To: "flyrotary" <flyrotary@lancaironline.net>
Subject: ECU wiring
Date: Wed, 28 Apr 2004 21:25:06 -0500
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Hi, fellow rotary enthusiasts.  My 13b is running pretty well with my Micro
Tech ECU.  I keep thinking that even though it's running OK, I might have
something wired incorrectly, or that could be improved upon. I know that
most of you are using Tracy's ECU, but since they both accomplish the same
task, I thought I could ask a couple of questions to compare my system to
Tracy's.
      The wiring schematic shows a red wire going from the positive side of
the battery, through a 30 amp fuse, and to one side of the injectors. That
would put power to the injectors at all times, even if the ignition switch
is in the OFF position.  I understand that the injectors, however will not
fire until the ECU sends a ground signal to the other wire on the injector.
Is this common practice?  Does Tracy's system work in a similar manner?
      The schematic shows the red wires that go to the 4 Bosch coils goes
through the ignition switch first. That made sense to me.
     I have a small terminal strip on the cold side of the firewall that
gets it's power straight from the ignition switch, so I could easily swap
the "constantly hot" wire that goes from the positive side of my battery to
the injectors, disconnect it and attach it to the "ignition on" power strip
so that the injectors only get power with the ignition switch in the ON
position.
      Not sure if this really matters....I wasn't so sure it would be good
to have constant power going to the injectors from the battery.  However,
that's how the heavy starter wire is....Direct power to the starter from the
positive side of the battery.
      I sure would appreciate any and all opinions on this.  It does run OK
as is....I'm just wondering if there are any safety concerns, etc about
leaving power to one side of the injectors even when the plane is not being
used.
      Thanks for everyone's attempt in clearing this up for me.  Paul
Conner, 13b powered SQ2000 in Mobile, AL