DYNOJET: TT AT vs PV Basic AT
Road Master
Joined: Mar 2007
Posts: 1,177
Likes: 23
What I guess I should have said is the AFR Target table was set to 14.68 that for some reason the Harley world rounds down to 14.6 AFR.
The front cylinder was still running the Target Tune wideband. I had the two wire NB in the rear cylinder hooked up only to the scope.
Andy
The front cylinder was still running the Target Tune wideband. I had the two wire NB in the rear cylinder hooked up only to the scope.
Andy
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
Well I missed that part.. Not sure you can say it's targeting 14.7 just by looking at the scope trace.. If the motor ain't completely warmed up the AFR can be all over the place.. I would think that a log file would show what the ECM is doing.. From what I've seen the o2 sensing on even heated widebands can be pretty noisy until the motor has some temp..
Probably why the ECM was set up to ignore the sensor input until a certain engine temp.
I agree. It really goes back to the log file. With what is out on the market today and how simple it is to record a log file. I can't see doing any type of test without it. Just as I can't see posting anything without posting the log file to go with it.
Without it. It is just like me making the statement. This number seven smells like purple. It's a statement I can't prove correct but the bigger issue. You can't prove it is incorrect. It is way too far out of context. Too much info is missing.
Road Master
Joined: Mar 2007
Posts: 1,177
Likes: 23
The scope trace does prove the motor was very close to 14.7 AFR.
You can also see that the switching can easily change in a few of engine cycles, and does. It is not switching at the tooth level or with every engine cycle.
You can also see that the switching can easily change in a few of engine cycles, and does. It is not switching at the tooth level or with every engine cycle.
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
Here is what the actual voltage coming off a narrow band really looks like on a digital scope. This is my Harley running open loop and idling with fueling set very close to 14.7 AFR. You will see the voltage going up and down switch about half way thru the video as the O2 sensor sniffs AFRs slightly above or below 14.7 AFR.
So, is it open loop or closed loop? If the sensor that was connected to the ECM was out of the exhaust and reading free air, and the CLI was showing 100. I would say something is wrong. It seems that the CLI would be showing that it is trying to add fuel because free air would be lean, no? Unless the sensor was so far out of range. It was ignoring the data, but you should get an error code unless TT removes these codes.
I have no idea how you could have the front cylinder showing closed loop corrections and the rear reading 100. 100 can mean more than it is perfect and why or how would the rear cylinder be hunting around a switching point with out a working closed loop feed back?
Why would Andy ever set up a target around stoich? He has stated over and over how his bike doesn't run very well at this target and he wont set his target this lean. He believes in nothing leaner than 14.
Just a couple of things that don't add up for me. That raise questions and should raise question and doubt for all of us.
Have fun learning how to weed through the BS.
Stellar HDF Member
Joined: Sep 2009
Posts: 2,114
Likes: 666
The way I understand it:
Chicken and the egg here.
Say the system sees lean so it drives afr rich - it is then read by the 02 sensors as rich...the ECM then leans the afr...then the o2 reports lean and the ECM then drives the afr rich...and the beat goes on.
This is why they are called switching sensors...cause they are using them from driving rich to driving afr lean/rich/lean/rich continually.
Rarely do I see LSU4.x broadband sensors as the afr dictator during a race.
The top teams know the LSU4.x limitations and choose to do tuning with real lab-quality widebands because they don't have the same accuracy limitations as the LSU4.x sensors.
Chicken and the egg here.
Say the system sees lean so it drives afr rich - it is then read by the 02 sensors as rich...the ECM then leans the afr...then the o2 reports lean and the ECM then drives the afr rich...and the beat goes on.
This is why they are called switching sensors...cause they are using them from driving rich to driving afr lean/rich/lean/rich continually.
Rarely do I see LSU4.x broadband sensors as the afr dictator during a race.
The top teams know the LSU4.x limitations and choose to do tuning with real lab-quality widebands because they don't have the same accuracy limitations as the LSU4.x sensors.
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
Road Master
Joined: Mar 2007
Posts: 1,177
Likes: 23
Channel 1 was hooked to a wire wrapped around the rear plug wire. That will give a voltage spike every time the plug wire amperage and voltage spikes. That is how a TinyTach works. It is the essence of how a coil has worked for years.
Andy
Andy
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Road Master
Joined: Mar 2007
Posts: 1,177
Likes: 23
Channel 1 was hooked to a wire wrapped around the rear plug wire. That will give a voltage spike every time the plug wire amperage and voltage spikes. That is how a TinyTach works. It is the essence of how a coil has worked for years.
Andy
Andy
HD EFI Guru
Joined: Jan 2008
Posts: 4,494
Likes: 4,779
The real issue is Andy misleading people like he always tries to do, Once again he got caught.
The HD/Delphi system operates O2 sensors on a 5 vdc feed voltage. So I knew just by looking at his test right away it was bogus. If he would just start telling the truth about things, instead of ever time twisting things around for whatever he thinks its going to gain him, things would and could be different.
All he has done is shown what might be a HD O2 sensor in an exhaust system that might be a HD running unconnected. It does not represent how a HD/Delphi O2 system works at all, and that is just a fact.
Andy
If you take this as a personal insult, what should everyone else on this site take your false and misleading post as?
The HD/Delphi system operates O2 sensors on a 5 vdc feed voltage. So I knew just by looking at his test right away it was bogus. If he would just start telling the truth about things, instead of ever time twisting things around for whatever he thinks its going to gain him, things would and could be different.
All he has done is shown what might be a HD O2 sensor in an exhaust system that might be a HD running unconnected. It does not represent how a HD/Delphi O2 system works at all, and that is just a fact.
Andy
If you take this as a personal insult, what should everyone else on this site take your false and misleading post as?