X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from exchange.carey.wa.edu.au ([118.82.44.212] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTPS id 4486810 for flyrotary@lancaironline.net; Thu, 30 Sep 2010 00:42:51 -0400 Received-SPF: none receiver=logan.com; client-ip=118.82.44.212; envelope-from=stevei@carey.asn.au Received: from exchange.carey.local ([10.10.0.5]) by exchange.carey.local ([10.10.0.5]) with mapi; Thu, 30 Sep 2010 12:42:06 +0800 From: To: Date: Thu, 30 Sep 2010 12:42:17 +0800 Subject: Re: [FlyRotary] Re: Auto tune/oxygen sensor Thread-Topic: [FlyRotary] Re: Auto tune/oxygen sensor Thread-Index: ActgWdXAQRMKynwoTBOjcCibwnW6rg== Message-ID: <3C605ECB-FD87-4697-AF7D-325997253244@carey.asn.au> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_3C605ECBFD874697AF7D325997253244careyasnau_" MIME-Version: 1.0 --_000_3C605ECBFD874697AF7D325997253244careyasnau_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Ed, I believe your description is right on. So autotune is a function of feedback to the EC2 from the EM2/3's O2 sensor= . Steve Izett On 30/09/2010, at 3:06 AM, Ed Anderson wrote: Al, is correct in that the EC does not directly interface with the O2 senso= r - however, because the autotune option does requires the EM2/3 (at least = I think I recall that being the case) to which the O2 sensor is connected= to, I suspect the following is a likely description of how the autotune fu= nction works. My understanding that - the EM2 is a component of the Auto Tune system of t= he EC. I suspect that the EM2 has a circuit to read the O2 sensor voltage. If the sensor is putting out around 0.450 volts (450 millivolts), then the= air/fuel ratio is close to stoichometric ratio of 14.7:1 air/fuel. If the= EC triggers the injectors and they produce a mixture that is richer than 1= 4.7:1 then the O2 voltage increases. This voltage swing is probably detect= ed by the EM2 and a mixture correction signal sent to the EC to reduce the = pulse width being sent to trigger the injectors thereby reducing the air/fu= el ratio and bringing it back to Stoichometric. Should the O2 voltage drop= below 450 millivolts (indicating leaner that 14.7:1), that deviation is se= nse by the EM2 and a correction sent to the EC to richen the mixture by inc= reasing pulse width of signal sent to injectors. So no EM2 - no autotune function, no Operational O2 sensor also equals no= AutoTune function. But, just a SWAG on my part, Tracy may provide the correct description if h= e gets back to the local Colorado Library {:>). Ed From: Al Gietzen Sent: Wednesday, September 29, 2010 2:42 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Auto tune/oxygen sensor Bill; The EC is not a closed loop system =96 does not use the O2 sensor output = =96 unless something has changed recently. Al -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf 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=92t think it is only used for setting the map table. YMMV Bill B ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf 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=92s 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 Rino ----- 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=92s 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 s= ame 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, bu= t 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 un= it. Cable colour allocations for the Universal Oxygen Sensor are as follows, sensor output signal wire =3D black, sensor heater element cables =3D White ( Note - heater is not polarity sensitive ) Sensor signal ground ( where used ) =3D 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 migh= t 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 an= d 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 E= C-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 wha= t car it came from. Anyone have the specs on what this sensor is? Bill Schertz KIS Cruiser #4045 N343BS Phase I testing ________________________________ The contents of this email are confidential and intended only for the named= recipients of this e-mail. If you have received this e-mail in error, you = are hereby notified that any use, reproduction, disclosure or distribution = or the information contained in this e-mail is prohibited. Please notify th= e sender immediately and then delete/destroy the e-mail and any printed cop= ies. All liability for viruses is excluded to the fullest extent of the law= . --_000_3C605ECBFD874697AF7D325997253244careyasnau_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Ed, I believe your description is right on.
So autotune is a function of feedback to the EC2 from the EM2/3's O2 s= ensor.

Steve Izett
On 30/09/2010, at 3:06 AM, Ed Anderson wrote:

Al, is correct in that the EC does not directly i= nterface with the O2 sensor - however, because the autotune option does req= uires the EM2/3 (at least I think I recall that being the case)  = to  which the O2 sensor is connected to, I suspect the following is a likely description of how the autotune function works.<= /font>
 
My understanding that - the EM2 is a component of= the Auto Tune system of the EC. 
 
 I suspect that the EM2 has a circuit to rea= d the O2 sensor voltage. 
 
 If the sensor is putting out around 0.450 v= olts (450 millivolts), then the air/fuel ratio is close to stoichometric ra= tio of 14.7:1 air/fuel.  If the EC triggers the injectors and they pro= duce a mixture that is richer than 14.7:1 then the O2 voltage increases.  This voltage swing is probably detected by= the EM2 and a mixture correction signal sent to the EC to reduce the pulse= width being sent to trigger the injectors thereby reducing the air/fuel ra= tio and bringing it back to Stoichometric.  Should the O2 voltage drop below 450 millivolts (indicating leaner that 14= .7:1), that deviation is sense by the EM2 and a correction sent to the EC t= o richen the mixture by increasing pulse width of signal sent to injectors.=
 
So no EM2 - no autotune function, no Operational =  O2 sensor  also equals no AutoTune function. 
 
But, just a SWAG on my part, Tracy may provide th= e correct description if he gets back to the local Colorado Library {:>)= .
 
Ed
 

From: Al Gietzen
Sent: Wednesd= ay, September 29, 2010 2:42 PM
Subject: [Fly= Rotary] Re: Auto tune/oxygen sensor

Bill;

 

The EC is not a closed loop syst= em =96 does not use the O2 sensor output =96 unless something has changed r= ecently.

 

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 Tr= acy recommends in the instructions.  I think the controller uses that = input to maintain the mixture where you set it.  I don=92t think it is only used for setting the map table.  YMMV

 

Bill B

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On B= ehalf Of Al Gi= etzen
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=92s what I have also; and I= think mine has something close to 150 hrs and still going fine.  I se= ldom burn avgas, so that helps.
I think one needs the O2 sensor for auto tune.
Yes, it does.  As I underst= and it; with the knobs centered the EM tunes to mid-range on the O2 sensor;= roughly stoichometric.

 

Al

 

 

Rino
----- Original Message -----
From: Ed Anderson
Sent: Wednesday, September 29, 2010 11:05 AM
Subject: [FlyRotary] Re: Auto tune/oxygen sensor

 

Bill, if it=92s a one wire sensor, then just about any of the &q= uot;universal" 1 wire O2 sensors you find in your auto store will work= . 

 

 If multiwire (I.e. has a heater element and a separate sen= sor ground wire), then you need to get one with the same number of wires.&n= bsp; 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 i= s 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 all= ocations for the Universal Oxygen Sensor are as follows,

sensor output = signal wire =3D black, sens= or heater element cables =3D

White ( Note - h= eater is not polarity sensitive ) Sensor signal ground

( where used ) = =3D Grey

Important: The c= able 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 par= ts guy might try to do because they all have 5 -6 wires and might get confu= sed with a Narrow band O2 sensor with a heater.

 

Ed

 

From: Bill Schertz
Sent: Wednesday, September 29, 2010 9:10 AM
Subject:<= span class=3D"Apple-converted-space"> [FlyRotary] Auto tune/oxygen sensor

 

Was going to do some auto tune in the air yesterday, to get to s= ome regions of the performance map that can't be reached on the ground.

 

Took off and the O2 sensor indication completely disappeared fro= m 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 followin= g questions.

 

1. I believe that the oxygen sensor readout is only that, not us= ed by the EC-2 for control purposes.
2. When in auto tune, is the EM-2 looking at the sensor for indi= cations of which way to adjust the mixture? If not, what is the feedback me= chanism?

 

I went to the Auto parts store for a replacement, and ran into t= he 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


The contents of this email a= re confidential and intended only for the named recipients of this e-mail. = If you have received this e-mail in error, you are hereby notified that any= use, reproduction, disclosure or distribution or the information contained in this e-mail is prohibited. Please notify t= he sender immediately and then delete/destroy the e-mail and any printed co= pies. All liability for viruses is excluded to the fullest extent of the la= w.
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