John,
I have
seen similar results, though I have the opposite problem. Mine falters if I turn it to the lean
side, but Runs fine full rich. At
low RPM’s I can turn the mixture lean or rich, and the ratio gauge (and
engine) follows. At higher RPM’s
I am running in the center, or low center of the air ratio, but I can’t make
it run richer. It goes one light
richer with the mixture full rich, but that’s all. At several MAP positions, I can go to
mode 1 and push the button over and over, with no change, yet other MAP
positions change with no problem. I think that there are only so
many steps (looks like about 4 to me), and that is it. Maybe Tracey could verify that.
Steve
Brooks
-----Original
Message-----
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of John Slade
Sent: Thursday, July 01, 2004 10:31
PM
To: Rotary motors in
aircraft
Subject: [FlyRotary]
EC2 programming
Rotarians,
I'm
still trying to program my EC2. Here's what I did tonight:
I
checked the EGO sensor by heating it with a blow torch. Voltage varied between
0.9 when hot to 0 when flame removed. (See the "how to check an EGO sensor"
text below - does this sound right?).
I
started the engine on the ramp (at night so I could see the air/fuel (AF)
gauge ).
The
engine started fine on full rich with cold start on. I turned off the cold
start, brought the rpm up to 2500 and leaned to the center. Engine ran ok.
Turn toward rich and it falters, turn toward lean and it runs better. At full
lean it runs best. AF reading is in the center. If I move toward rich the
reading goes higher and engine falters past center.
Turn to
mode 3, move program knob to left and press store button. No effect. Press
again 6 times. Still no effect either on the engine or the AF reading. Turn to
mode 1. Move mixture to left. Move program knob to left. Press button. No
effect. Press button 4 times. Still no effect on AF reading or engine. I
turned on the cold start switch. No effect on the engine or the AF reading.
After
this I taxied up and down a bit at various rpm settings until the temps got
too high. The AF reading stayed pretty much in the center at all times. Maybe
one yellow bar on occasions. The engine runs quite well at all rpm, and
there wasn't much, if any, soot on the prop when I ran it with the mixture on
full lean.
I get
the impression that the program button isn't doing anything - but the B
computer has a copy of Tracy's original settings (I think) and the engine runs
worse when I switch to it, so I must have changed something on A. A
while back I checked that there's a ground on the proper pin when the program
button is pressed, and I checked continuity on all the wires from the control
panel pins to the EC2 pins. I guess I'll check all this again tomorrow.
Those
who've programmed an EC2 using the AF gauge - do you see an obvious effect
when you store a change? How many times do you have to press the button to get
a visible impact?
I know
we've been through all this before. I don't seem to be getting
anywhere.
Any
thoughts or suggestions welcome.
John
Slade (banging my head against the wall)
PS -
Does the EM2 give an air fuel reading? I hope so.
How to
check an EGO sensor.
Use a high
impedence DC voltmeter as above. Clamp the sensor in
a vice, or use a plier
or vice-grip to hold it. Clamp your
negative voltmeter lead to the case,
and the positive to the
output wire. Use a propane torch set to high and
the inner blue
flame tip to heat the fluted or perforated area of the
sensor.
You should see a DC voltage of at least 0.6 within 20
seconds.
If not, most likely cause is open circuit internally or
lead
fouling. If OK so far, remove from flame. You should see a
drop to
under 0.1 volt within 4 seconds. If not likely silicone
fouled. If still
OK, heat for two full minutes and watch for
drops in voltage. Sometimes,
the internal connections will open
up under heat. This is the same a loose
wire and is a failure.
If the sensor is OK at this point, and will switch
from high to
low quickly as you move the flame, the sensor is good. Bear
in
mind that good or bad is relative, with port fuel injection
needing
faster information than carbureted systems.
ANY O2 sensor that will
generate 0.9 volts or more when heated,
show 0.1 volts or less within one
second of flame removal, AND
pass the two minute heat test is good
regardless of age. When
replacing a sensor, don't miss the opportunity to
use the test
above on the replacement. This will calibrate your
evaluation
skills and save you money in the future. There is almost
always
*no* benefit in replacing an oxygen sensor that will pass
the
test in the first line of this
paragraph.