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.