Rich / Lean (o2) gauge function?
Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 3,374
Likes: 86
From: Corbin KY
Rich / Lean (o2) gauge function?
I installed a RICH / LEAN autometer gauge in the car and I am REALLY confused at what I am seeing.
until the car is warm (over 150) the gauge is off the scale (lean) that it does not even register any lights unless you start reving it up. Then it will sell back off the scale again.
After the car is warmed up and driving down the road the gauge will go on the high side of the stoich and read correct EXCEPT for every few minutes it goes off the scale on the lean side and them comes right back to the normal window of operation. When it does this it goes off the scale fast and not gradual.
Anybody had any experience with these gauges? Is this normal? If this is not normal what the heck is wrong with this stupid car that would cause the gauge to do this?
Thanks
Phil
until the car is warm (over 150) the gauge is off the scale (lean) that it does not even register any lights unless you start reving it up. Then it will sell back off the scale again.
After the car is warmed up and driving down the road the gauge will go on the high side of the stoich and read correct EXCEPT for every few minutes it goes off the scale on the lean side and them comes right back to the normal window of operation. When it does this it goes off the scale fast and not gradual.
Anybody had any experience with these gauges? Is this normal? If this is not normal what the heck is wrong with this stupid car that would cause the gauge to do this?
Thanks
Phil
Pro
Joined: Jul 2002
Posts: 703
Likes: 0
From: Milwaukee Wi
I dont think they tell you much. the nb02 is designed to toggle quickly over median voltage (.45) giving feedback to ECU and ECU adjusts mixture by long term trim(BLM) maintaining stoich. so you see it moving continuously rich/lean. With a AE-PE event you will see it go rich and if you let off gas you may see it eventually lean. some say you can read it to determine enrichment quantity in PE-WOT but that may be a reach. Datalogs will show the NB02 mvolt values moving up-down as well. Only a WB with A/F gauge willl give you meaningfull A/F info.
Le Mans Master
Joined: Apr 2005
Posts: 6,413
Likes: 9
From: The Old Dominion
It is based on the narrow-band O2, is that right? If so, they read 0mV until they start to warm up. This is interpreted as extremely lean, though the ECM ignores it (that's open loop mode).
Like Rohn said, a narrowband really isn't that useful except for the ECM to make fine adjustments to fueling.
Do you have headers or something that is keeping the sensor from staying hot?
Like Rohn said, a narrowband really isn't that useful except for the ECM to make fine adjustments to fueling.
Do you have headers or something that is keeping the sensor from staying hot?
Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 3,374
Likes: 86
From: Corbin KY
It is based on the narrow-band O2, is that right? If so, they read 0mV until they start to warm up. This is interpreted as extremely lean, though the ECM ignores it (that's open loop mode).
Like Rohn said, a narrowband really isn't that useful except for the ECM to make fine adjustments to fueling.
Do you have headers or something that is keeping the sensor from staying hot?
Like Rohn said, a narrowband really isn't that useful except for the ECM to make fine adjustments to fueling.
Do you have headers or something that is keeping the sensor from staying hot?
It does it in Close loop (putting in back in open loop) after the car is warm also.
It is a heated O2 from a 90 ZR1. I do have long tube headers.
Le Mans Master
Joined: Apr 2005
Posts: 6,413
Likes: 9
From: The Old Dominion
Yeah, it sounds like something is amiss, at least to me. Do you have a way to monitor the ECM's reported O2 values independent of the gauge? Maybe it's just the gauge is wonky or has some loose wiring?
Otherwise, presumably your O2 sensor isn't staying hot. Or maybe you have a misfire that causes it to read extremely lean. Or maybe just some loose wire somewhere?
Otherwise, presumably your O2 sensor isn't staying hot. Or maybe you have a misfire that causes it to read extremely lean. Or maybe just some loose wire somewhere?
Racer
Joined: Jun 2004
Posts: 391
Likes: 0
From: Lisle IL
CI 6-7-8-9-10 Veteran
I installed a RICH / LEAN autometer gauge in the car and I am REALLY confused at what I am seeing.
until the car is warm (over 150) the gauge is off the scale (lean) that it does not even register any lights unless you start reving it up. Then it will sell back off the scale again.
After the car is warmed up and driving down the road the gauge will go on the high side of the stoich and read correct EXCEPT for every few minutes it goes off the scale on the lean side and them comes right back to the normal window of operation. When it does this it goes off the scale fast and not gradual.
Anybody had any experience with these gauges? Is this normal? If this is not normal what the heck is wrong with this stupid car that would cause the gauge to do this?
Thanks
Phil
until the car is warm (over 150) the gauge is off the scale (lean) that it does not even register any lights unless you start reving it up. Then it will sell back off the scale again.
After the car is warmed up and driving down the road the gauge will go on the high side of the stoich and read correct EXCEPT for every few minutes it goes off the scale on the lean side and them comes right back to the normal window of operation. When it does this it goes off the scale fast and not gradual.
Anybody had any experience with these gauges? Is this normal? If this is not normal what the heck is wrong with this stupid car that would cause the gauge to do this?
Thanks
Phil
The gauge is worthless until you're at WOT.
Thread Starter
Melting Slicks
Joined: Dec 2006
Posts: 3,374
Likes: 86
From: Corbin KY
Truthfully, the car runs like CRAP all the time if you ask me.
1. Will NOT idle when cold. Have to play with throttle until temp is above 130 or so then it will idle.
2. Runs VERY VERY rich what seems like all the time. I can tell this because it smells like a 60's BB with 3X2.
3. When you nail it it takes off (after tires hook) and then somewhere around 3-3500 RPM it feels like it is on the bottle and starts pullling hard. With the engine combo I have this makes NO sence at all.
4. Some time you can take off and get in the throttle from a roll and it just blazes the tires. Next time it wont. Feels like it lost 50HP.
5. Throttle responce should be ALOT crisper. It is OK but does not rev (not under load) as it should. I think this has alot to do with the rich condition.
This is a complete new motor with a mail order tune and looks like I have alot of bugs to figure out. I am trying to just go 1 by 1 eliminating any and all issues. I really have not looked real hard into anything due to the brake booster took a crap and has a major vac leak when pressing the brake pedal and a very hard pedal. I am replacing this first and going from there.
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Instructor
Joined: Jun 2004
Posts: 247
Likes: 0
From: Derry nh
Does anyone know if this onboard "Test the O2 Sensor - Engine Running" using the ECM really works?
http://www.geocities.com/jgkov/FSMode.html?20085
http://www.geocities.com/jgkov/FSMode.html?20085
