From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Wednesday, September 29, 2010 12:07 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Auto tune/oxygen sensor
I have the BOSCH sensor 11027 and it works fine.
That’s what I have also; and I think mine has something close to 150 hrs and still going fine. I seldom burn avgas, so that helps.
I think one needs the O2 sensor for auto tune.
Yes, it does. As I understand it; with the knobs centered the EM tunes to mid-range on the O2 sensor; roughly stoichometric.
Al
----- Original Message -----
Sent: Wednesday, September 29, 2010 11:05 AM
Subject: [FlyRotary] Re: Auto tune/oxygen sensor
Bill, if it’s a one wire sensor, then just about any of the "universal" 1 wire O2 sensors you find in your auto store will work.
If multiwire (I.e. has a heater element and a separate sensor ground wire), then you need to get one with the same number of wires. If you get the same make O2 sensor, then the wires should be the same color.
Bosch has a wire chart which tells you which color wire is which - this may help. I always get a Bosch unit - they might cost a few bucks more, but they are generally good quality, available anywhere and you can find the wire color code. Here's the wiring color code for the "Universal" Bosch unit.
Cable colour allocations for the Universal Oxygen Sensor are as follows,
sensor output signal wire = black, sensor heater element cables =
White ( Note - heater is not polarity sensitive ) Sensor signal ground
( where used ) = Grey
Important: The cable allocations must be assigned correctly. Otherwise
the Sensor could be destroyed
Don't let them sell you a wide band O2 sensor which a novice parts guy might try to do because they all have 5 -6 wires and might get confused with a Narrow band O2 sensor with a heater.
Sent: Wednesday, September 29, 2010 9:10 AM
Subject: [FlyRotary] Auto tune/oxygen sensor
Was going to do some auto tune in the air yesterday, to get to some regions of the performance map that can't be reached on the ground.
Took off and the O2 sensor indication completely disappeared from the EM-2 display. Did one circuit of the airport and landed.
Discovered that the O2 sensor had failed (physically -- the top fell off and separated from the body). This caused me to raise the following questions.
1. I believe that the oxygen sensor readout is only that, not used by the EC-2 for control purposes.
2. When in auto tune, is the EM-2 looking at the sensor for indications of which way to adjust the mixture? If not, what is the feedback mechanism?
I went to the Auto parts store for a replacement, and ran into the problem that there are 100's of different oxygen sensors, and they need to know what car it came from. Anyone have the specs on what this sensor is?
Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing