I'm new at this, but I have been hanging around,sucking up info here for a long time. Here's the deal, Today I Installed my Scanmaster and went for a short ride. I noticed that my O2 numbers were all over the place. One sec they are reading 780 then 240, then 450. What gives? has anyone seen this before? Also, I know this thing gives me all sorts of great imformation, But where can I learn to make use of it all? I get the basics, but What are Cross Counts, Integraters, and Block learn? How do I use this info?
Goofy O2 Numbers
- Thread starter Sleeper-6
- Start date
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What you are seeing is normal...
Take a look at:
http://www.gnttype.org/maint/quickref.html
For the basics ...
Take a look at:
http://www.gnttype.org/maint/quickref.html
For the basics ...
Carolinaturbot6
Pride. Freedom. America
- Joined
- May 24, 2001
- Messages
- 285
Before Ken replied, I was trying to locate a page that had ALL of the codes/descriptions listed along w/ the parameters for you. I have yet to find one.
Ken's link does give you somewhere to start though.
I don't own a scanmaster, but I would have thought a list of parameters & settings would come with it.
The most important thing to monitor is the knock or knock retard.
I'll try & copy a link or two for ya that may help ya out.
Trouble code reference & descriptions:
http://www.gnttype.org/maint/malf.html
Sensor locations:
http://www.gnttype.org/maint/sensors.html
Additional links & info:http://www.geocities.com/rad87gn/tech/tech.html
Ken's link does give you somewhere to start though.
I don't own a scanmaster, but I would have thought a list of parameters & settings would come with it.
The most important thing to monitor is the knock or knock retard.
I'll try & copy a link or two for ya that may help ya out.
Trouble code reference & descriptions:
http://www.gnttype.org/maint/malf.html
Sensor locations:
http://www.gnttype.org/maint/sensors.html
Additional links & info:http://www.geocities.com/rad87gn/tech/tech.html
In closed loop, ie normal driving and idle, the ecm tries to maintain a 14.7:1 AFR. So it toggles the injectors plus width from short to long to run lean and rich to maintain that average. The amount of correction is noted in the ecm's scratch pad.
Cross counts are the number of times the O2 crosses the 14.7 voltage.
Block Learns are the long term corrections to maintain the average.
Integrator is the short term correction to maintain it
Carolinaturbot6
Pride. Freedom. America
- Joined
- May 24, 2001
- Messages
- 285
"There is nothing wrong with your chip or fuel delivery system, even in normal driving, when your BLM (Block Learn Mode) numbers are anywhere between 110 & 145. The car will still be running stoichiometrically correct no matter what the BLM numbers show, as long as they are between 110-145. Numbers below 128 show that the computer is taking away fuel & numbers above 128 show that the computer is adding fuel. In either case,the car is not running rich or lean! The BLM numbers basically show what fuel corrections the computer is making in order to keep fuel delivery stoichiometrically correct. BLM numbers will vary with types of gasoline, weather, & at idle when you turn on the a/c!
Now if your scan tool shows BLM numbers always way below 128 or way above 128, it shows that some fuel correction is necessary. Often this can be adjusted with the fuel pressure regulator. But still, the computer is working (only "harder") to keep the fuel mixture stoichiometrically correct. If BLM numbers are always below 110 or always above 145, that's when you start looking for a fueling problem.
Just to elaborate a bit, the cc's (cross counts) should normally be changing quite a bit. A sign of a "lazy" o2 sensor on it's way out is when the cc's are changing either very slowly or not changing at all.
Hopefully this isn't confusing you although it can seem a little overwhelming at first. It gets much easier once you get used to reading the sensor info & asking questions. HTH
Now if your scan tool shows BLM numbers always way below 128 or way above 128, it shows that some fuel correction is necessary. Often this can be adjusted with the fuel pressure regulator. But still, the computer is working (only "harder") to keep the fuel mixture stoichiometrically correct. If BLM numbers are always below 110 or always above 145, that's when you start looking for a fueling problem.
Just to elaborate a bit, the cc's (cross counts) should normally be changing quite a bit. A sign of a "lazy" o2 sensor on it's way out is when the cc's are changing either very slowly or not changing at all.
Hopefully this isn't confusing you although it can seem a little overwhelming at first. It gets much easier once you get used to reading the sensor info & asking questions. HTH
Ok, Now I get it! But what i'm still trying to figure out is how do you get an accurate O2 sensor reading when it swings so quickly from one extreme to the next? I always figured it would stay Roughly around the same area so I could get an idea of my Rich\lean condition. It flips from on to the next and they may be 400-500 Mv apart. ?
The only time you'll see it pretty steady is during a WOT run ...
Otherwise it's doing as it is supposed to (as Bruce pointed out), and that's switching back and forth rapidly in response to the exhaust content.
That allows the ECM to keep the catalytic converter happy (it needs a little excess fuel to keep temps up) and on average maintain the desired A/F ratio.
Otherwise it's doing as it is supposed to (as Bruce pointed out), and that's switching back and forth rapidly in response to the exhaust content.
That allows the ECM to keep the catalytic converter happy (it needs a little excess fuel to keep temps up) and on average maintain the desired A/F ratio.
Can you help with this O2 problem?
You guys sound like you gave pretty good advice on that last problem, hoping you can help me out with mine.
My problem is my O2 sensor is not giving me a reading on my scanmaster. I am getting all 000's. I used to get a reading of about 390 at startup and idle. I recently had my passenger side header removed to weld a crack. After that I ran a tank of leaded race fuel and turned the boost up a little on my adjustable wastegate (only 1 turn and about 16 lbs). I am running a Red's 93 chip.
About the time I ran through the tank of gas (couple hundred miles), My O2's went to zero and I got a error code 44 after the engine warmed up. 02 reading was 000's immediately.
Ordered a new 02 sensor from Kirban's, put it on, same problem.
I also noticed that my BLM's and INT now run about 160 at idle, and go to 128 at part throttle. My scanmaster reads everything, so I know its working.
Any ideas? Do I have a bad sensor wire? How do I diagnose and fix this problem?
Any help would be greatly appreciated!
Chris
Chris
You guys sound like you gave pretty good advice on that last problem, hoping you can help me out with mine.
My problem is my O2 sensor is not giving me a reading on my scanmaster. I am getting all 000's. I used to get a reading of about 390 at startup and idle. I recently had my passenger side header removed to weld a crack. After that I ran a tank of leaded race fuel and turned the boost up a little on my adjustable wastegate (only 1 turn and about 16 lbs). I am running a Red's 93 chip.
About the time I ran through the tank of gas (couple hundred miles), My O2's went to zero and I got a error code 44 after the engine warmed up. 02 reading was 000's immediately.
Ordered a new 02 sensor from Kirban's, put it on, same problem.
I also noticed that my BLM's and INT now run about 160 at idle, and go to 128 at part throttle. My scanmaster reads everything, so I know its working.
Any ideas? Do I have a bad sensor wire? How do I diagnose and fix this problem?
Any help would be greatly appreciated!
Chris
Chris
Carolinaturbot6
Pride. Freedom. America
- Joined
- May 24, 2001
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- 285
Chris, I do not have the experience nor the smarts to tell you exactly how to diagnose it. But, if it were me, I would start looking at the wiring itself...as you mentioned. I would think it must be the wiring due to the fact that the ecm isn't reading zilch from the o2.
It may be a good idea to give John a call at Caspers Electronics (847-247-0484). He is a very helpful & knowledgeable guy.
www.casperselectronics.com
It may be a good idea to give John a call at Caspers Electronics (847-247-0484). He is a very helpful & knowledgeable guy.
www.casperselectronics.com
Carolina Turbot6,
Thanks for the reply. I never would have been able to figure out this one on my own either. I got lucky with some diagnostic help on this one Sunday! Was at show with a couple other guys with GN's, and we brought a volt meter and tested the wire and O2 sensor and both were fine. We pulled my ECM and one from another GN, swapped the chip, and reinstalled in mine, BINGO, problem diagnosed, bad ECM!
So now I just need to buy a new ECM and I am off and running.
Many thanks to Rod, Ken and Dan for their help on Sunday!
Chris
Thanks for the reply. I never would have been able to figure out this one on my own either. I got lucky with some diagnostic help on this one Sunday! Was at show with a couple other guys with GN's, and we brought a volt meter and tested the wire and O2 sensor and both were fine. We pulled my ECM and one from another GN, swapped the chip, and reinstalled in mine, BINGO, problem diagnosed, bad ECM!
So now I just need to buy a new ECM and I am off and running.
Many thanks to Rod, Ken and Dan for their help on Sunday!
Chris
sixgun86gn
six offender
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- Feb 10, 2002
- Messages
- 3,470
My car has been doing that for a while too,just periodically.I may have to check into that with my ecm.thanks for opening up a new idea for me.I think that may be my part throttle knock problem too.
