Another thing to try is to set the MAP table write width to
minimum (in mode
2) before doing the mode 1 programming.
Some EC2 users avoid the transition stumble by moving the
transition point
to a different manifold pressure (in Mode 7).
Unfortunately, Chuck has an
early EC1 controller which has a fixed manifold pressure
for stagging.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
I tried carefully programming on the ground with the
write width set at
minimum and very slowly increasing the throttle. Still no
joy. As soon as I
got to 16" MP it started surging at 1 second interval. Then
I went flying
and programmed at a safe altitude with minimum write width.
I finally got a
good result by hitting the program button at just the right
time, at minimum
RPM of the "surge" and setting it richer in that area. Now
it is much
better! Three things were working against me, 1. the O2
sensor responds
slower at low power, 2. there is no way to "see" what is
actually going on
in the MAP table programming, and 3. MP starts increasing
again below a
certain RPM.
I think #3 comes from having the secondary ports open all
the time and the
late closing of the secondary intake port. Of course when
MP rises, so does
the amount of fuel, making it too rich when it doesn't need
it. I was
considering installing an accumulator in the vacuum line to
the ECU to slow
the response, and thus surge cycle time, to where it might
be easier to
program. A software or hardware integrator (?) should
accomplish the same
thing. We don't need fast throttle response in an airplane.
The EC1 is so
easy to program at 17" MP or above that I just did not
expect it to be so
critical in the staging area. I had it programmed real
close before, but I
was trying different ignition timing, and probably needed
new spark plugs,
and got the programming all screwed up by trying to use the easy
programmability (is that a word?) feature of the EC1 to
compensate. I will
try to leave the EC1 alone after this. Anyway, Thanks, guys
for the help. I
get stuck in a rut thinking about a problem a certain way
and it sure helps
to see things from a different perspective.
And thanks, Tracy for the generous offer to upgrade my EC1.
I may do that
later when I run out of things to do :-) but as long as I
can make the EC1
work, I will keep it so I will not have to rewire
everything for the new
connector on the EC2.
Chuck Dunlap