I have found in my installation that around

15-16" Hg

manifold and

approx 2800-3000 rpm that I need to program the

system in much

finer

increments of Manifold pressure and rpm than

elsewhere.  If

I do not,

everything is fine at idle and everything is fine higher

than 3000 rpm but

as I increase from 2000 up through 3000 the air/fuel

indicator will shift

from rich to an lean indication and the engine

will stumble

a moment.

Interestingly enough I don't notice it in the air.

Ed Anderson

Thanks, Ed I will try that. It is hard to get it to

stay at a steady

MP

around 16" because it appears to lean out as it

drops below the

staging

point, then MP increases and secondaries kick in

again. It surges at

about a

one second cycle. I can stop the surging by

manually richening the

mixture.

I don't notice it in the air either, except

sometimes when throttled

back on

short final. Mostly does it on the ground when

taxiing by onlookers

:-)

Chuck Dunlap

I encounter the same conditions.  But, I find if I sort

of ignore the MP

reading and advance the rpm in stages of 100-200rpm

increments between

about

2500-3000 and reset the processors MAP by using mode 1

so that the

manual

mixture control set at 1200 gives me a rich indication

on the air/fuel

meter

that takes care of the stumble.

Ed Anderson

Tracy needs to put a bit of hysterisis(s?) in the software.
Either that or gradually transition from two injectors to four.

It is easy to get theses kinds of control problems when

using computers

in real time closed loop systems. There are delays in

certain sensors.

Perhaps the MAP, perhaps the intake manifold temp (highly

likely) perhaps

even the RPM (somewhat likely).

Try moving the throttle very very slowly.

Paul Lamar

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

Chuck, I think you mentioned that you had trouble getting auto gas.
Am I wrong? 100LL on the O2 sensor?

Paul Lamar
 
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