Al,

I don’t have a clue how it works, but the O2 sensor connects to the monitor.  It will indicate the mixture graph on the monitor.  If you set the mixture on the controller and then climb and descend, the mixture will stay the same as you go up and down.  The amount of air is changing, so something is changing the amount of fuel.  It knows what the barometric pressure is, so maybe it uses that???

 

Bill

 

 

Bill;

 

The EC is not a closed loop system – does not use the O2 sensor output – unless something has changed recently.

 

Al

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Wednesday, September 29, 2010 8:53 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Auto tune/oxygen sensor

 

Bosch 11027 is the O2 sensor that Tracy recommends in the instructions.  I think the controller uses that input to maintain the mixture where you set it.  I don’t think it is only used for setting the map table.  YMMV

 

Bill B

 

 

 

----- Original Message -----

From: Ed Anderson

To: Rotary motors in aircraft

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.

 

Ed

 

From: Bill Schertz

Sent: Wednesday, September 29, 2010 9:10 AM

To: Rotary motors in aircraft

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