X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from aspensprings.uwyo.edu ([129.72.10.32] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTPS id 4486417 for flyrotary@lancaironline.net; Wed, 29 Sep 2010 15:38:04 -0400 Received-SPF: none receiver=logan.com; client-ip=129.72.10.32; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht2.uwyo.edu (ponyexpress-ht2.uwyo.edu [10.84.60.209]) by aspensprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id o8TJbNTq010867 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Wed, 29 Sep 2010 13:37:23 -0600 (MDT) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht2 ([10.84.60.209]) with mapi; Wed, 29 Sep 2010 13:37:22 -0600 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Wed, 29 Sep 2010 13:37:21 -0600 Subject: RE: [FlyRotary] Re: Auto tune/oxygen sensor Thread-Topic: [FlyRotary] Re: Auto tune/oxygen sensor Thread-Index: ActgCatpgWGKAwSfSkaQ5h5AUrO1bwAAXIce Message-ID: 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_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FDAponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FDAponyexpressmb_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable My take on the autotune function of the EM2/3 is that it uses the O2 sensor= output to make corrections to the table in the EC2/3 in the same way as on= e would do it manually. It would only do this when the autotune function i= s active and a completely corrected table would only be obtained after perf= orming the autotune in various flight regimes. After the autotune function= is deactivated, the EC2/3 continues to use its corrected table with no fur= ther changes to it unless they are made manually or by another autotune ses= sion. I don't think the EC2/3 uses the O2 sensor output either directly or= indirectly from the EM2/3 to make instantaneous changes to mixture. Not h= aving an EM2/3, this is just my impression of the information I've seen. S= urely there must be a discription of the autotune function in the EM2/3 ins= tructions? My older EC2's have a connection to an O2 sensor and the O2 sensor data can= be recovered by interrogating the EC2. This O2 sensor data does not appea= r to be actually used by the EC2, however. Steve Boese ________________________________ From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of = Ed Anderson [eanderson@carolina.rr.com] Sent: Wednesday, September 29, 2010 1:06 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Auto tune/oxygen sensor 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 --_000_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FDAponyexpressmb_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
My take on the autotune function of the EM2/3 is that it uses the O2 s= ensor output to make corrections to the table in the EC2/3 in the same way = as one would do it manually.  It would only do this when the autotune = function is active and a completely corrected table would only be obtained after performing the autotune in various flig= ht regimes.  After the autotune function is deactivated, the EC2/3 con= tinues to use its corrected table with no further changes to it unless they= are made manually or by another autotune session.  I don't think the EC2/3 uses the O2 sensor output either di= rectly or indirectly from the EM2/3 to make instantaneous changes to mixtur= e.  Not having an EM2/3, this is just my impression of the inform= ation I've seen.  Surely there must be a discription of the autotune function in the EM2/3 instructions?
 
My older EC2's have a connection to a= n O2 sensor and the O2 sensor data can be recovered by interrogating the EC= 2.  This O2 sensor data does not appear to be actually used by th= e EC2, however.
 
Steve Boese
=  
From: Rotary moto= rs in aircraft [flyrotary@lancaironline.net] On Behalf Of Ed Anderson [eand= erson@carolina.rr.com]
Sent: Wednesday, September 29, 2010 1:06 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Auto tune/oxygen sensor

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
 

Sent: Wednesday, September 29, 2010 2:42 PM
Subject: [FlyRotary] Re: Auto tune/oxygen sensor

Bill;

 

The EC is n= ot a closed loop system =96 does not use the O2 sensor output =96 unless so= mething has changed recently.

 

Al

 

-----Origi= nal Message-----
From: Rotary motors in airc= raft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry=
Sent: Wednesday, September = 29, 2010 8:53 AM
To: Rotary motors in aircra= ft
Subject: [FlyRotary] Re: Au= to tune/oxygen sensor

 

Bosch 11027 is the O2 sensor that Tracy recommends in the ins= tructions.  I think the controller uses that input to maintain the mixture where you set it.  I don=92t think it i= s only used for setting the map table.  YMMV

 

Bill B

 

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 aircra= ft
Subject: [FlyRotary] Re: Au= to 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 need= s the O2 sensor for auto tune.

Yes, it does.  As I understand it; with the knobs ce= ntered the EM tunes to mid-range on the O2 sensor; roughly stoichometric.

 

Al

 

 

Rino

----- Original M= essage -----

<= font size=3D"2" face=3D"Arial">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 "universal" 1 wire = O2 sensors you find in your auto store will work. 

 

 If multiwi= re (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 colo= r.

 

  Bosch has= a wire chart which tells you which color wire is which  - this may he= lp.  I always get a Bosch unit - they might cost a few bucks more, but they are generally good quality, available anywhere and yo= u 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 =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. Ot= herwise

the Sensor could be destroyed

 

Don't let them s= ell you a wide band O2 sensor which a novice parts guy might try to do beca= use they all have 5 -6 wires and might get confused with a Narrow band O2 sensor with a heater.

 

Ed=

=  

<= b>From: Bill Schertz

<= b>Sent: Wednesday, September 29, 2010 9:10 AM

<= b>Subject: [FlyRotary] Auto tune/oxygen sensor

 

Was going to do = some auto tune in the air yesterday, to get to some regions of the performa= nce 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 tha= t 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 adj= ust the mixture? If not, what is the feedback mechanism?

 

I went to the Au= to parts store for a replacement, and ran into the problem that there are 1= 00's of different oxygen sensors, and they need to know what car it came from. Anyone have the specs on what this sen= sor is?

 

 

Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing

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