WB-O2 results contradict BLMs
05-04-2009, 05:14 PM
#1
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Car: Chevy Suburban-ish "Camaro" 1991
Engine: 383
Transmission: 4L80e
WB-O2 results contradict BLMs
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$85
I am running an Innovate LC-1 WideBand O2 sensor. It is installed just ahead of my cat after the 2-1 connector. I have a heated O2 for the ECM that is upstream and only picks up from the left bank of exhaust.
Datalogging gives me BLM results that are slightly Lean (BLM = 135 range). WBO2 is reading a bit rich at around 12:1. At one point my BLM was showing 171 while WBO2 was reading quite rich at 10.5:1.
Now I guess the ECM is adding fuel as the BLM numbers are above 128, but how do I tune this out? Can anyone offer advise as to what is going on here? It seems that if I tune in reaction to my BLM numbers then I would be increasing my VE's and making things richer (per the WBO2).
I am a bit stumped and not sure where to go from here.
Thanks for any help,
$85
I am running an Innovate LC-1 WideBand O2 sensor. It is installed just ahead of my cat after the 2-1 connector. I have a heated O2 for the ECM that is upstream and only picks up from the left bank of exhaust.
Datalogging gives me BLM results that are slightly Lean (BLM = 135 range). WBO2 is reading a bit rich at around 12:1. At one point my BLM was showing 171 while WBO2 was reading quite rich at 10.5:1.
Now I guess the ECM is adding fuel as the BLM numbers are above 128, but how do I tune this out? Can anyone offer advise as to what is going on here? It seems that if I tune in reaction to my BLM numbers then I would be increasing my VE's and making things richer (per the WBO2).
I am a bit stumped and not sure where to go from here.
Thanks for any help,
05-05-2009, 11:05 AM
#2
Re: WB-O2 results contradict BLMs
Something is not right. I assume you recalibtrated the WB? If you have WB set up to A/F you should see 14.7 as stoich even for E10. My NB is in driver side ext just behind collector flange. WB is passanger side about 16 inches further back(duals). My A/F shows 14.9/1 on average on WB(possibly seeing some reversion). As you are aware a 135 BLM should show 14.7 + - on WB. all it is doing is adding fuel to maintain stoich value.
05-05-2009, 01:11 PM
#3
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Car: Chevy Suburban-ish "Camaro" 1991
Engine: 383
Transmission: 4L80e
Re: WB-O2 results contradict BLMs
Ronny,
That is what I thought. I could not understand how at a steady cruise it would not be 14.7:1 as the BLM's should be correcting the fueling (BLM's are w/in a reasonable range). I did calibrate the WB per the instructions during installation.
Could this be an issue with my NB? It seems to be responding correctly, but I am at a loss.
I should add that for the most part the engine is running well, but my Fuel Mileage sucks. I am getting about 8mpg out of my un-aerodynamic, 6,000lbs, 4x4 "Camaro"
thanks,
That is what I thought. I could not understand how at a steady cruise it would not be 14.7:1 as the BLM's should be correcting the fueling (BLM's are w/in a reasonable range). I did calibrate the WB per the instructions during installation.
Could this be an issue with my NB? It seems to be responding correctly, but I am at a loss.
I should add that for the most part the engine is running well, but my Fuel Mileage sucks. I am getting about 8mpg out of my un-aerodynamic, 6,000lbs, 4x4 "Camaro"
thanks,
Last edited by Keith91sub; 05-05-2009 at 01:22 PM.
05-05-2009, 01:42 PM
#4
Re: WB-O2 results contradict BLMs
No CE-SES light? Do you have CE SES light in car? in your datalogs you should see the swing of mvolts back forth for NB02. if not seeing that it is not functional or maybe not in closed loop. coolant temp needs to be adequate and it needs to be placed properly in ext stream. My non heated NB would fall out of CL when I was scruising at 55 or would take quite a while to flip on cold cold start. due to location at header/collector flange. A heated 02 solved that issue.
05-05-2009, 08:29 PM
#5
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Car: Chevy Suburban-ish "Camaro" 1991
Engine: 383
Transmission: 4L80e
Re: WB-O2 results contradict BLMs
No SES. NBo2 seems to be fine and does cross over. Coolant temp is right at or close to 180 degrees.
05-06-2009, 03:15 AM
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Car: 86 vette
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Transmission: 700R4
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Re: WB-O2 results contradict BLMs
A big block 6000# 4x4 "Camaro" should live closer to 12 mpg.
8 MPG would be about right for a 12-10:1 afr, believe your WB.
Look at the plugs should show signs of richness.
I would say you are running in PE mode even at steady 55 mph.
Get a vacuum gauge and watch where your numbers are at steady speed.
A data log would be helpful.
8 MPG would be about right for a 12-10:1 afr, believe your WB.
Look at the plugs should show signs of richness.
I would say you are running in PE mode even at steady 55 mph.
Get a vacuum gauge and watch where your numbers are at steady speed.
A data log would be helpful.
05-06-2009, 11:24 AM
#7
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Car: Chevy Suburban-ish "Camaro" 1991
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Transmission: 4L80e
Re: WB-O2 results contradict BLMs
Motor is a SBC 383.
I like your comment on PE mode. I will review the logs and monitor that. I will also check the plugs.
Thanks again.
I like your comment on PE mode. I will review the logs and monitor that. I will also check the plugs.
Thanks again.
A big block 6000# 4x4 "Camaro" should live closer to 12 mpg.
8 MPG would be about right for a 12-10:1 afr, believe your WB.
Look at the plugs should show signs of richness.
I would say you are running in PE mode even at steady 55 mph.
Get a vacuum gauge and watch where your numbers are at steady speed.
A data log would be helpful.
8 MPG would be about right for a 12-10:1 afr, believe your WB.
Look at the plugs should show signs of richness.
I would say you are running in PE mode even at steady 55 mph.
Get a vacuum gauge and watch where your numbers are at steady speed.
A data log would be helpful.
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05-06-2009, 02:48 PM
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Re: WB-O2 results contradict BLMs
I agree with Pandin-you may be in PE. You might want to check you NB & WB sensors at idle & light load to see if they agree. If they don't, then troubleshoot that FIRST!
05-06-2009, 06:06 PM
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Car: Chevy Suburban-ish "Camaro" 1991
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Re: WB-O2 results contradict BLMs
WB - NB tend to agree: If WB is showing 13.5, NB is 600ish. They both jump around a bit but I can follow the pattern.
I am pretty sure that my PE is set at a reasonable level, but I will check tonight.
I will also try my stock PROM and see how the motor responds.
thanks,
I am pretty sure that my PE is set at a reasonable level, but I will check tonight.
I will also try my stock PROM and see how the motor responds.
thanks,
05-06-2009, 06:21 PM
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Car: 86 vette
Engine: 383
Transmission: 700R4
Axle/Gears: 3.07
Re: WB-O2 results contradict BLMs
At idle your WB and NB may read different, you need to check it at light load and steady speed. Your cam, if it has a lot of duration, will mess with the low air flows.
At peak torque the air flow stabilizes, but you have to be at a light load. Just think about a big lopey cam and and low (lugging) rpm at 55 mph, mileage will be real bad. Like if your cam's peak torque is at 4000 rpm and you are running at 2000 rpm.
I would data log in 4th and in 3rd to see if the O2's still match or not.
The old smog carb's power valve (PE) would engage at 14 in of vacuum, before smog it was 6 inches. This made a difference of 12 mpg vs 20 mpg in a light car (350 1976 nova) and the trucks were even worse. If a carb 5000# 4x4 427cid can get 13 mpg, a TPI should at least match it.
This was done by raising (richer) the steady speed AFR and lowering the PE engagement, spark was advanced a little also.
At peak torque the air flow stabilizes, but you have to be at a light load. Just think about a big lopey cam and and low (lugging) rpm at 55 mph, mileage will be real bad. Like if your cam's peak torque is at 4000 rpm and you are running at 2000 rpm.
I would data log in 4th and in 3rd to see if the O2's still match or not.
The old smog carb's power valve (PE) would engage at 14 in of vacuum, before smog it was 6 inches. This made a difference of 12 mpg vs 20 mpg in a light car (350 1976 nova) and the trucks were even worse. If a carb 5000# 4x4 427cid can get 13 mpg, a TPI should at least match it.
This was done by raising (richer) the steady speed AFR and lowering the PE engagement, spark was advanced a little also.
05-06-2009, 06:53 PM
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Re: WB-O2 results contradict BLMs
I've got a similar problem. I have the narrow band output from the LC-1 going to a gauge and it also goes in a different direction than my BLMs. I thought that I'd wired the gauge wrong and I was going to swap it.....now I'm not sure.
05-11-2009, 12:13 AM
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Re: WB-O2 results contradict BLMs
I ran my Stock bin today to see what happens and the trend was simmilar. WBO2 was still a bit rich at mid 12:1 - mid 13:1. BLM's were pretty close to 128 w/ NBO2 looking normal.
This has me so confused. Could this be due to my Holley TBI unit (new style injectors)?
This has me so confused. Could this be due to my Holley TBI unit (new style injectors)?
05-11-2009, 08:56 AM
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Re: WB-O2 results contradict BLMs
Reasons for spread in NB vs WB AFR.
WB calibration
NB calibration
Different sensor locations which cause different
temperatures
Bank to bank AFR
burning times in the pipe
Exhaust leaks
vacuum leaks
injector unbalance/leaks
Ground difference
These are just a few things that could cause a WB vs NB AFR difference.
WB calibration
NB calibration
Different sensor locations which cause different
temperatures
Bank to bank AFR
burning times in the pipe
Exhaust leaks
vacuum leaks
injector unbalance/leaks
Ground difference
These are just a few things that could cause a WB vs NB AFR difference.
05-12-2009, 11:38 PM
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Re: WB-O2 results contradict BLMs
My latest trial:
I burned a chip with a lower Base Pulse Width Constant. In Open loop the WBO2 was showing a bit lean 15ish. When in Closed loop it reverted back to the 12-13 levels. Some of the BLM's were still quite high in the 140 range, some were at 128. When I got home I pulled a few plugs and they showed evidence of the engine running Lean. They were fairly white and a few of the insulators were a bit blistered.
I am begining to doubt my WBO2. I will try to recalibrate it but am a bit woried as when I tried to pull the O2 sensor it was freezing in the bung. I will try again soon.
I burned a chip with a lower Base Pulse Width Constant. In Open loop the WBO2 was showing a bit lean 15ish. When in Closed loop it reverted back to the 12-13 levels. Some of the BLM's were still quite high in the 140 range, some were at 128. When I got home I pulled a few plugs and they showed evidence of the engine running Lean. They were fairly white and a few of the insulators were a bit blistered.
I am begining to doubt my WBO2. I will try to recalibrate it but am a bit woried as when I tried to pull the O2 sensor it was freezing in the bung. I will try again soon.
05-14-2009, 01:24 AM
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Car: 86 vette
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Re: WB-O2 results contradict BLMs
I am wondering what blm cells (rpm and load) are 128 and what cells (rpm and load) are 140. If the idle and low rpm load are 128 and the higher rpm load is 140 then this can be corrected by changing the lower map values a bit. This will level the BLM's, after they are level then you can adjust the BPWC to raise or lower all the BLM's. After they are all at 128 then see how the plugs look.
There are other adjustments to make to correct the O2 feedback, to raise or lower rich/lean but keep the 128 BLM.
I run a MAF so I can't give the exact table but it is call "O2 C/L R/L Threshold vs Airflow " in the ARAP 6E.
Your 1991 is a speed density right.
There are other adjustments to make to correct the O2 feedback, to raise or lower rich/lean but keep the 128 BLM.
I run a MAF so I can't give the exact table but it is call "O2 C/L R/L Threshold vs Airflow " in the ARAP 6E.
Your 1991 is a speed density right.
05-19-2009, 02:00 AM
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Re: WB-O2 results contradict BLMs
I have an extended cab 4x4 "camaro" and my fuel economy isn't great, but its not 8mpg. Even with a 383 and bored tb.
05-19-2009, 06:48 AM
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Re: WB-O2 results contradict BLMs
It is possible that 1 of your 02 sensors is bad. I have an LC-1 and I used the narrowband output from it to feed the ECM and the wideband output from it to feed the gauge. You have to be sure that it is calibrated properly but it will eliminate any differences from having 2 different sensors in 2 different locations.
I also agree with Pandin that you may need to play with the mV's of the 02 sensor vs airflow, or whatever table you SD guys have. I am playing with that myself right now. That sets what AFR the blms are targeting. If you have enough cam that some fresh air is going out the exhaust then 14.7 on the wideband will not work for you because that fresh air is being read. Computer doesn't know that and thinks that is air that didn't burn during the combustion process and will therefore add more fuel. Not sure this is what is going on with your setup or not but worth looking into.
You guys crack me up with the extended cab 4X4 6000lb Camaros. In that case, I have a 3200 lb. 2 seater "Camaro" with flip open headlights.
I also agree with Pandin that you may need to play with the mV's of the 02 sensor vs airflow, or whatever table you SD guys have. I am playing with that myself right now. That sets what AFR the blms are targeting. If you have enough cam that some fresh air is going out the exhaust then 14.7 on the wideband will not work for you because that fresh air is being read. Computer doesn't know that and thinks that is air that didn't burn during the combustion process and will therefore add more fuel. Not sure this is what is going on with your setup or not but worth looking into.
You guys crack me up with the extended cab 4X4 6000lb Camaros. In that case, I have a 3200 lb. 2 seater "Camaro" with flip open headlights.
05-19-2009, 03:47 PM
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Re: WB-O2 results contradict BLMs
never mind I got it
Last edited by Drumer919; 05-19-2009 at 03:58 PM.
06-01-2009, 01:47 PM
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Re: WB-O2 results contradict BLMs
I am still struggling with the same problem. Over the weekend I re-calibrated my WBO2 sensor and improved the ground on my NB. My WB02 is consistantly showing anywhere from 11:1 to 12.8:1 while my BLM's are stable mostly at around 135 - Integrator stable at 128. I do have one BLM cell that spikes - cruizing around 65 mph w/ KPA around mid60's (BLM cell 10) I get a spike in BLM's to 170ish. In that range where the BLM spikes, the WBO2 drops to 10.5:1 range.
I pulled my plugs and they look Good (a bit on the lean side if anything). The only scenario that I can come up with is that there is an exhaust leak causing the NB to false lean. The ECM richens it up and the WBO2 is reading accurate. But why would my plugs look good if I am running in the 11-12 range AFR?
Following are the catagories from TunerCat. TunerPro has fewer items than this. I can not seem to find any kind of PE table. One suggestion above is that I have been constantly in PE. Can anyone suggest what would be the equivalant of PE in this list? Any other suggestions?
Thanks much for any help!
I pulled my plugs and they look Good (a bit on the lean side if anything). The only scenario that I can come up with is that there is an exhaust leak causing the NB to false lean. The ECM richens it up and the WBO2 is reading accurate. But why would my plugs look good if I am running in the 11-12 range AFR?
Following are the catagories from TunerCat. TunerPro has fewer items than this. I can not seem to find any kind of PE table. One suggestion above is that I have been constantly in PE. Can anyone suggest what would be the equivalant of PE in this list? Any other suggestions?
Thanks much for any help!
C.A.T.S. Tuner PCM_85 Parameter List
(ECM Configuration File Version AK)
ECM Switch Parameters
ECM Switch Parameters
EGR RPM/MAP Select, X=RPM
Electronic Governor Option (X = Enabled)
Err 24, Veh. Speed Err Enable, X=Enabled
Trans Press Switch Error, Err 28
Err 32, EGR Error Enable, X=Enabled
Err 43, ESC Err Enable, X=Enabled
O2 Voltage Low Error, Err 44
O2 Voltage High Error, Err 45
Trans Temp High Error, Err 58
Trans Temp Low Error, Err 59
Trans Slip Error, Err 68
Trans Force Motor Error, Err 73
Quad Driver 1 Shift B Error, Err 81
Quad Driver 1 Shift A Error, Err 82
Quad Driver 1 Error, Err 83
Undefined Ratio Error, Err 85, X=Enabled
Low Ratio Error, Err 86, X=Enabled
High Ratio Error, Err 87, X=Enabled
Electronic Governor Option (X = Enabled)
Err 24, Veh. Speed Err Enable, X=Enabled
Trans Press Switch Error, Err 28
Err 32, EGR Error Enable, X=Enabled
Err 43, ESC Err Enable, X=Enabled
O2 Voltage Low Error, Err 44
O2 Voltage High Error, Err 45
Trans Temp High Error, Err 58
Trans Temp Low Error, Err 59
Trans Slip Error, Err 68
Trans Force Motor Error, Err 73
Quad Driver 1 Shift B Error, Err 81
Quad Driver 1 Shift A Error, Err 82
Quad Driver 1 Error, Err 83
Undefined Ratio Error, Err 85, X=Enabled
Low Ratio Error, Err 86, X=Enabled
High Ratio Error, Err 87, X=Enabled
ECM Constants
Fuel Cut Off Engine Speed
Fuel Resume Engine Speed
Initial Spark Advance
Main Spark Bias
Cool Compensation Spark Advance Bias
Maximum Spark Advance
Maximum Spark Retard
Min. Cool. Temp. to Enable Spark Retard
Bypass WOT Delay, (Eng Speed)
Wide Open Throttle Delay
Base Pulse Width Constant
Number of Cylinders
Decel Enleanment Delta MAP Factor
EGR On, (TPS)
EGR Off, (TPS)
EGR On (Eng Speed)
EGR Off, (Eng. Speed)
Low MAP EGR On
Low MAP EGR Off
EGR Off, (MAP)
EGR On, (MAP)
Min. Coolant Temp. To Enable EGR
Maximum RPM To Enable Block Learn
Minimum MAP To Enable Block Learn
Maximum MAP To Enable Block Learn
Force Open Loop Fuel For Idle, (Speed)
Force Open Loop Fuel For Idle, (TPS)
Open Loop Idle Fuel Enable RPM Threshold
Open Loop Idle Fuel Disable RPM Thresh.
Open Loop Idle Fuel Enable Delay Timer
Max. AFR For 1st Time Open Loop Idle
Maximum Open Loop Idle AFR
Min. Coolant to Enable Closed Loop Fuel
Closed Lp Timer Enable (Cold/Warm Eng.)
Closed Lp Enable Timer, (Cold Eng)
Closed Lp Enable Timer (Warm Eng.)
Accel 'Pump Shot' For IAC At Idle
Minimum BLM Value
Maximum BLM Value
Minimum Integrator Value
Maximum Integrator Value
Async To Sync Fuel MAP Threshold
Async To Sync Fuel RPM Threshold
Sync To Async Fuel MAP Threshold
Sync To Async Fuel RPM Threshold
Async-->Sync BPW (Min)
Maximum Async Injector Pulse Width
Minimum Async Injector Pulse Width
Delta O2 Volt Window for Fast Rich/Lean
Error Thresh. for Integration Correction
Rich O2 Sensor Voltage At Idle
Lean O2 Sensor Voltage At Idle
Mean R/L O2 Sensor Voltage At Idle
Proportional Gain Flow Factor at Idle
Proportional Duration Offset at Idle
Integrator Delay Bias at Idle
Positive Error Scale Factor
Error Correction Factor at Idle
IAC Park To Run Position Decay Delay
%TPS Threshold For Closed Throttle
Time Treshold To Enable IAC Kickdown
Desired Governor RPM
Low Governor Disable RPM
Desired Governor Vehicle Speed
Governor Disable Speed Hysteresis
Governor Light On RPM Threshold
Governor Overspeed Fuel Cutoff RPM
Governor Overspeed Fuel Resume RPM
Governor Overspeed Fuel Cutoff Speed
Governor Overspeed Fuel Resume Speed
Mechanical 1st Gear Ratio
Mechanical 2nd Gear Ratio
Mechanical 3rd Gear Ratio
Kickdown Mode Enable %TPS Threshold
Kickdown Mode Disable %TPS Threshold
Power Steering Stall Enable RPM Thresh.
Power Steering Stall Disable RPM Thresh.
TCC Enable Coolant Temp. Threshold
TCC Disable Coolant Temp. Threshold
TCC Enable Transmission Temp. Threshold
TCC Disable Transmission Temp. Threshold
Neg. Delta %TPS TCC Release Threshold
Delta %TPS TCC Off Time
Min TPS to Enable TCC - Low MPH
Min TPS to Enable TCC - High MPH
TCC Disable TPS Threshold - Low MPH
TCC Disable TPS Threshold - High MPH
Low-High MPH Thresh. for TCC TPS Limits
High-Low MPH Thresh. for TCC TPS Limits
Lower Adaptive Learn Trans Temp Thresh.
Upper Adaptive Learn Trans Temp. Thresh.
PROM ID
Fuel Resume Engine Speed
Initial Spark Advance
Main Spark Bias
Cool Compensation Spark Advance Bias
Maximum Spark Advance
Maximum Spark Retard
Min. Cool. Temp. to Enable Spark Retard
Bypass WOT Delay, (Eng Speed)
Wide Open Throttle Delay
Base Pulse Width Constant
Number of Cylinders
Decel Enleanment Delta MAP Factor
EGR On, (TPS)
EGR Off, (TPS)
EGR On (Eng Speed)
EGR Off, (Eng. Speed)
Low MAP EGR On
Low MAP EGR Off
EGR Off, (MAP)
EGR On, (MAP)
Min. Coolant Temp. To Enable EGR
Maximum RPM To Enable Block Learn
Minimum MAP To Enable Block Learn
Maximum MAP To Enable Block Learn
Force Open Loop Fuel For Idle, (Speed)
Force Open Loop Fuel For Idle, (TPS)
Open Loop Idle Fuel Enable RPM Threshold
Open Loop Idle Fuel Disable RPM Thresh.
Open Loop Idle Fuel Enable Delay Timer
Max. AFR For 1st Time Open Loop Idle
Maximum Open Loop Idle AFR
Min. Coolant to Enable Closed Loop Fuel
Closed Lp Timer Enable (Cold/Warm Eng.)
Closed Lp Enable Timer, (Cold Eng)
Closed Lp Enable Timer (Warm Eng.)
Accel 'Pump Shot' For IAC At Idle
Minimum BLM Value
Maximum BLM Value
Minimum Integrator Value
Maximum Integrator Value
Async To Sync Fuel MAP Threshold
Async To Sync Fuel RPM Threshold
Sync To Async Fuel MAP Threshold
Sync To Async Fuel RPM Threshold
Async-->Sync BPW (Min)
Maximum Async Injector Pulse Width
Minimum Async Injector Pulse Width
Delta O2 Volt Window for Fast Rich/Lean
Error Thresh. for Integration Correction
Rich O2 Sensor Voltage At Idle
Lean O2 Sensor Voltage At Idle
Mean R/L O2 Sensor Voltage At Idle
Proportional Gain Flow Factor at Idle
Proportional Duration Offset at Idle
Integrator Delay Bias at Idle
Positive Error Scale Factor
Error Correction Factor at Idle
IAC Park To Run Position Decay Delay
%TPS Threshold For Closed Throttle
Time Treshold To Enable IAC Kickdown
Desired Governor RPM
Low Governor Disable RPM
Desired Governor Vehicle Speed
Governor Disable Speed Hysteresis
Governor Light On RPM Threshold
Governor Overspeed Fuel Cutoff RPM
Governor Overspeed Fuel Resume RPM
Governor Overspeed Fuel Cutoff Speed
Governor Overspeed Fuel Resume Speed
Mechanical 1st Gear Ratio
Mechanical 2nd Gear Ratio
Mechanical 3rd Gear Ratio
Kickdown Mode Enable %TPS Threshold
Kickdown Mode Disable %TPS Threshold
Power Steering Stall Enable RPM Thresh.
Power Steering Stall Disable RPM Thresh.
TCC Enable Coolant Temp. Threshold
TCC Disable Coolant Temp. Threshold
TCC Enable Transmission Temp. Threshold
TCC Disable Transmission Temp. Threshold
Neg. Delta %TPS TCC Release Threshold
Delta %TPS TCC Off Time
Min TPS to Enable TCC - Low MPH
Min TPS to Enable TCC - High MPH
TCC Disable TPS Threshold - Low MPH
TCC Disable TPS Threshold - High MPH
Low-High MPH Thresh. for TCC TPS Limits
High-Low MPH Thresh. for TCC TPS Limits
Lower Adaptive Learn Trans Temp Thresh.
Upper Adaptive Learn Trans Temp. Thresh.
PROM ID
Tables
ECM Switch Table
ECM Constant Table
Main Spark Advance Vs. Load Vs. RPM
Cool Compensation Spark Advance Vs. Load
Power Enrichment Spark Vs. RPM
Start Up Spark Advance Vs. Coolant Temp.
Startup Spark Advance Decay Delay Vs. Coolant Temp
Startup Spark Advance Decay Factor Vs. Cool. Temp.
Knock Attack Rate Vs. RPM (Deg/msec)
Knock Recovery Rate Vs. RPM (%/sec)
Maximim Knock Retard Vs. RPM (in WOT)
Maximim Knock Retard Vs. MAP
EGR Spark Advance Correction
Volumetric Efficiency Vs. RPM Vs. Load
Base Pulse Constant Vs. % Avail. EGR Vs. Air Flow
Desired % EVRV Vs. MAP Vs. RPM
% Available EGR Vs. Vacuum Vs. EVRV % Duty Cycle
TPS Threshold Vs. RPM For WOT
TPS Threshold Vs. RPM For WOT, (Fast)
WOT Air Fuel Ratio Vs. RPM
Pump Shot Vs. Differential TPS
Pump Shot Vs. Differential MAP
Open Loop Air Fuel Ratio Vs. Coolant Temp.
Choke Enrichment Factor Vs. Coolant Temp.
Choke AFR Decay Multiplier Vs. Coolant Temp.
AFR Time Out Decay Rate Vs. Air Flow
Crank Air Fuel Ratio Vs. Coolant Temp.
Decel Enleanment Coolant Factor Vs. Coolant Temp.
IAC Steps Vs Coolant Temp.
Target Idle RPM Vs. Coolant Temp.
IAC Motor Reset Position Vs. Baro.
IAC Motor Power Steering Stall Offset Vs. Baro.
Integrator Delay Vs. Air Flow
Mean Rich/Lean O2 Voltage Threshold Vs. Air Flow
Rich O2 Voltage Threshold Vs. Air Flow
Lean O2 Voltage Threshold Vs. Air Flow
Slow O2 Filter Time Constant Vs. Air Flow
Proportional Counts Vs. Slow Filtered O2 Error
Prop. Term Duration Vs. Slow Filtered O2 Error
Proportional Duration Offset Vs. Air Flow
Proportional Gain Flow Factor Vs. Air Flow
Integrator Delay Multiplier Vs. Slow O2 Error
Main Line Pressure, 0 - 64 MPH
Main Line Pressure, 64 - 128 MPH
Normal Mode Upshift/Downshift Vs. MPH Vs. TPS
Kickdown Up/Down Shift Points
Performance Mode Upshift/Downshift Vs. MPH Vs. TPS
Torgue Converter Release MPH Vs. TPS
Torgue Converter Engage MPH Vs. TPS
TCC Apply Operating Point Vs. %TPS
TCC Release Operating Point Vs. %TPS
Minimum TCC Duty Cycle Vs. Torque Pressure
Line Pressure Modifier Vs. Gear Vs. TPS
Down Shift Pressure Modifier 2 -> 1 Vs. MPH
Down Shift Pressure Modifier 3 -> 2 Vs. MPH
Down Shift Pressure Modifier 4 -> 3 Vs. MPH
Line Pressure Modifier In WOT Vs. RPM
Desired Shift Time Vs. %TPS
Adaptive Pressure Modifier Vs. Shift Time Error
Gear Ratio Limits For Error Diagostics 85, 86 & 87
ECM Constant Table
Main Spark Advance Vs. Load Vs. RPM
Cool Compensation Spark Advance Vs. Load
Power Enrichment Spark Vs. RPM
Start Up Spark Advance Vs. Coolant Temp.
Startup Spark Advance Decay Delay Vs. Coolant Temp
Startup Spark Advance Decay Factor Vs. Cool. Temp.
Knock Attack Rate Vs. RPM (Deg/msec)
Knock Recovery Rate Vs. RPM (%/sec)
Maximim Knock Retard Vs. RPM (in WOT)
Maximim Knock Retard Vs. MAP
EGR Spark Advance Correction
Volumetric Efficiency Vs. RPM Vs. Load
Base Pulse Constant Vs. % Avail. EGR Vs. Air Flow
Desired % EVRV Vs. MAP Vs. RPM
% Available EGR Vs. Vacuum Vs. EVRV % Duty Cycle
TPS Threshold Vs. RPM For WOT
TPS Threshold Vs. RPM For WOT, (Fast)
WOT Air Fuel Ratio Vs. RPM
Pump Shot Vs. Differential TPS
Pump Shot Vs. Differential MAP
Open Loop Air Fuel Ratio Vs. Coolant Temp.
Choke Enrichment Factor Vs. Coolant Temp.
Choke AFR Decay Multiplier Vs. Coolant Temp.
AFR Time Out Decay Rate Vs. Air Flow
Crank Air Fuel Ratio Vs. Coolant Temp.
Decel Enleanment Coolant Factor Vs. Coolant Temp.
IAC Steps Vs Coolant Temp.
Target Idle RPM Vs. Coolant Temp.
IAC Motor Reset Position Vs. Baro.
IAC Motor Power Steering Stall Offset Vs. Baro.
Integrator Delay Vs. Air Flow
Mean Rich/Lean O2 Voltage Threshold Vs. Air Flow
Rich O2 Voltage Threshold Vs. Air Flow
Lean O2 Voltage Threshold Vs. Air Flow
Slow O2 Filter Time Constant Vs. Air Flow
Proportional Counts Vs. Slow Filtered O2 Error
Prop. Term Duration Vs. Slow Filtered O2 Error
Proportional Duration Offset Vs. Air Flow
Proportional Gain Flow Factor Vs. Air Flow
Integrator Delay Multiplier Vs. Slow O2 Error
Main Line Pressure, 0 - 64 MPH
Main Line Pressure, 64 - 128 MPH
Normal Mode Upshift/Downshift Vs. MPH Vs. TPS
Kickdown Up/Down Shift Points
Performance Mode Upshift/Downshift Vs. MPH Vs. TPS
Torgue Converter Release MPH Vs. TPS
Torgue Converter Engage MPH Vs. TPS
TCC Apply Operating Point Vs. %TPS
TCC Release Operating Point Vs. %TPS
Minimum TCC Duty Cycle Vs. Torque Pressure
Line Pressure Modifier Vs. Gear Vs. TPS
Down Shift Pressure Modifier 2 -> 1 Vs. MPH
Down Shift Pressure Modifier 3 -> 2 Vs. MPH
Down Shift Pressure Modifier 4 -> 3 Vs. MPH
Line Pressure Modifier In WOT Vs. RPM
Desired Shift Time Vs. %TPS
Adaptive Pressure Modifier Vs. Shift Time Error
Gear Ratio Limits For Error Diagostics 85, 86 & 87
06-01-2009, 02:02 PM
#21
Re: WB-O2 results contradict BLMs
TPS Threshold Vs. RPM For WOT
TPS Threshold Vs. RPM For WOT, (Fast)
I think stock is around 70%. Some place it lower. Trucks I believe are even higher. I would set to 50-70%. Keep in mind it affects fuel economy.
I wonder if you are seeing some effect with EGR or charcoal canister purge? Mine are disabled. I would think a vac leak would skew the BLMs higher and put your VE tables at >100 if you are adjusting VE table. I had a header flange leak that caused high values in VE table as I was following BLM.
EDIT My charcoal canister is vented to atmosphere currently. EGR was removed in .bin and the physical side. Blocked off with plate.
TPS Threshold Vs. RPM For WOT, (Fast)
I think stock is around 70%. Some place it lower. Trucks I believe are even higher. I would set to 50-70%. Keep in mind it affects fuel economy.
I wonder if you are seeing some effect with EGR or charcoal canister purge? Mine are disabled. I would think a vac leak would skew the BLMs higher and put your VE tables at >100 if you are adjusting VE table. I had a header flange leak that caused high values in VE table as I was following BLM.
EDIT My charcoal canister is vented to atmosphere currently. EGR was removed in .bin and the physical side. Blocked off with plate.
Last edited by Ronny; 06-01-2009 at 02:05 PM.
06-02-2009, 08:49 AM
#22
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Re: WB-O2 results contradict BLMs
I had mine looking real good in closed loop, idle bounced around 14.7 on the wideband and integrator hung right around 128. BLMS locked at 128. I then locked the integrator and set the CL coolant temp to max to lock it in open loop and wow. All of a sudden the wideband was showing 17.5 to 18:1. All of the part throttle driving was showing richer though, around 12.5. Amazing thing is, the plugs look great when the wideband reads 12.5, give or take. When running closed loop with the integrator perfect and the wideband showing 14.7, the plugs where too white and too clean. Found that my bucking or cut-out problem at very light throttle is much less noticeable when running the 12.5:1 afr. When I am almost completely off the gas the afr is about 11:1, and when I'm on the gas moderately the afr is about 13.8:1. This seems to be what my particular combo likes the best. I totally hate to not run closed loop but I think with the 230/236 cam and the rest of my combo that open loop and rich AFR's is the only way to go for me.
Is it possible that 14.7 is not the optimum target for part throttle driving with a big cam and great flowing (especially exhaust flow) heads? Haven't gotten a lot of driving in yet but it also preliminarily seems that the fuel mileage is not worse running the afr's around 12.5:1.
Is it possible that 14.7 is not the optimum target for part throttle driving with a big cam and great flowing (especially exhaust flow) heads? Haven't gotten a lot of driving in yet but it also preliminarily seems that the fuel mileage is not worse running the afr's around 12.5:1.
06-02-2009, 11:30 AM
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Re: WB-O2 results contradict BLMs
The questions you need to ask your selves.
1: Is the WB reading the AFR of the combustion chamber or the Exhaust pipe.
2: Is this the true AFR or a calculated one assuming that all the fuel/air is burnt up.
The reason I present these questions, is that the more unburnt fuel that is present with Oxygen the more incorrect the reading, WB or NB.
Here is the difference between a factory cam set up and an large over lap cam.
With the extra scavenging effects of a "modified" exhaust system, the correct AFR at 14.7 is pulled past the combustion chamber and on into the exhaust pipe. This "correct AFR" is already past the chamber when the exhaust valve closes, so it can add no power to the engine it is just a lost input.
But wait, what happens on the opening of the exhaust valve, a hot and burning "match" lights off this mixture and it burns. Long tube headers hold more of this mixture separate from other cylinder firings then stock or shorty's. Remember how you get high EGT with retarded spark and exhaust pops when too rich. People need to understand this, because their O2 readings are "incorrect" because of this.
This is also why open loop runs different then closed loop. Open loop just feeds the "proper" AFR to the engine (like a carb) and will not correct for the "extra" Oxygen being pulled through the over lap.
This is very similar to trying to read a WB or NB placed after a catalytic converter, how would you know what is burnt in the chamber and what is burnt in the cat.
A stock cam makes this a very different animal, then a highly overlapped one.
The mixture leaving the combustion chamber is a blend of new mixture and burnt mixture, with the earlier exhaust being more burnt and the later being more fuel/air (unburnt).
This "complete scavenging" does too things for you, it increases power, less exhaust gas in the "new charge" will produce more power then a diluted one and sending raw fuel/air down the pipe will hurt your MPG, not to mention the increase in exhaust pipe temps due to increased "burning down the pipe".
By allowing the burnt exhaust to be "left/added" to the new charge, it lowers NO2 emissions. This "leave some burnt mix" is one reason "smog" heads are so poor for "performance".
1: Is the WB reading the AFR of the combustion chamber or the Exhaust pipe.
2: Is this the true AFR or a calculated one assuming that all the fuel/air is burnt up.
The reason I present these questions, is that the more unburnt fuel that is present with Oxygen the more incorrect the reading, WB or NB.
Here is the difference between a factory cam set up and an large over lap cam.
With the extra scavenging effects of a "modified" exhaust system, the correct AFR at 14.7 is pulled past the combustion chamber and on into the exhaust pipe. This "correct AFR" is already past the chamber when the exhaust valve closes, so it can add no power to the engine it is just a lost input.
But wait, what happens on the opening of the exhaust valve, a hot and burning "match" lights off this mixture and it burns. Long tube headers hold more of this mixture separate from other cylinder firings then stock or shorty's. Remember how you get high EGT with retarded spark and exhaust pops when too rich. People need to understand this, because their O2 readings are "incorrect" because of this.
This is also why open loop runs different then closed loop. Open loop just feeds the "proper" AFR to the engine (like a carb) and will not correct for the "extra" Oxygen being pulled through the over lap.
This is very similar to trying to read a WB or NB placed after a catalytic converter, how would you know what is burnt in the chamber and what is burnt in the cat.
A stock cam makes this a very different animal, then a highly overlapped one.
The mixture leaving the combustion chamber is a blend of new mixture and burnt mixture, with the earlier exhaust being more burnt and the later being more fuel/air (unburnt).
This "complete scavenging" does too things for you, it increases power, less exhaust gas in the "new charge" will produce more power then a diluted one and sending raw fuel/air down the pipe will hurt your MPG, not to mention the increase in exhaust pipe temps due to increased "burning down the pipe".
By allowing the burnt exhaust to be "left/added" to the new charge, it lowers NO2 emissions. This "leave some burnt mix" is one reason "smog" heads are so poor for "performance".
06-02-2009, 11:45 AM
#24
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Re: WB-O2 results contradict BLMs
The questions you need to ask your selves.
1: Is the WB reading the AFR of the combustion chamber or the Exhaust pipe.
2: Is this the true AFR or a calculated one assuming that all the fuel/air is burnt up.
The reason I present these questions, is that the more unburnt fuel that is present with Oxygen the more incorrect the reading, WB or NB.
Here is the difference between a factory cam set up and an large over lap cam.
With the extra scavenging effects of a "modified" exhaust system, the correct AFR at 14.7 is pulled past the combustion chamber and on into the exhaust pipe. This "correct AFR" is already past the chamber when the exhaust valve closes, so it can add no power to the engine it is just a lost input.
But wait, what happens on the opening of the exhaust valve, a hot and burning "match" lights off this mixture and it burns. Long tube headers hold more of this mixture separate from other cylinder firings then stock or shorty's. Remember how you get high EGT with retarded spark and exhaust pops when too rich. People need to understand this, because their O2 readings are "incorrect" because of this.
This is also why open loop runs different then closed loop. Open loop just feeds the "proper" AFR to the engine (like a carb) and will not correct for the "extra" Oxygen being pulled through the over lap.
This is very similar to trying to read a WB or NB placed after a catalytic converter, how would you know what is burnt in the chamber and what is burnt in the cat.
A stock cam makes this a very different animal, then a highly overlapped one.
The mixture leaving the combustion chamber is a blend of new mixture and burnt mixture, with the earlier exhaust being more burnt and the later being more fuel/air (unburnt).
This "complete scavenging" does too things for you, it increases power, less exhaust gas in the "new charge" will produce more power then a diluted one and sending raw fuel/air down the pipe will hurt your MPG, not to mention the increase in exhaust pipe temps due to increased "burning down the pipe".
By allowing the burnt exhaust to be "left/added" to the new charge, it lowers NO2 emissions. This "leave some burnt mix" is one reason "smog" heads are so poor for "performance".
1: Is the WB reading the AFR of the combustion chamber or the Exhaust pipe.
2: Is this the true AFR or a calculated one assuming that all the fuel/air is burnt up.
The reason I present these questions, is that the more unburnt fuel that is present with Oxygen the more incorrect the reading, WB or NB.
Here is the difference between a factory cam set up and an large over lap cam.
With the extra scavenging effects of a "modified" exhaust system, the correct AFR at 14.7 is pulled past the combustion chamber and on into the exhaust pipe. This "correct AFR" is already past the chamber when the exhaust valve closes, so it can add no power to the engine it is just a lost input.
But wait, what happens on the opening of the exhaust valve, a hot and burning "match" lights off this mixture and it burns. Long tube headers hold more of this mixture separate from other cylinder firings then stock or shorty's. Remember how you get high EGT with retarded spark and exhaust pops when too rich. People need to understand this, because their O2 readings are "incorrect" because of this.
This is also why open loop runs different then closed loop. Open loop just feeds the "proper" AFR to the engine (like a carb) and will not correct for the "extra" Oxygen being pulled through the over lap.
This is very similar to trying to read a WB or NB placed after a catalytic converter, how would you know what is burnt in the chamber and what is burnt in the cat.
A stock cam makes this a very different animal, then a highly overlapped one.
The mixture leaving the combustion chamber is a blend of new mixture and burnt mixture, with the earlier exhaust being more burnt and the later being more fuel/air (unburnt).
This "complete scavenging" does too things for you, it increases power, less exhaust gas in the "new charge" will produce more power then a diluted one and sending raw fuel/air down the pipe will hurt your MPG, not to mention the increase in exhaust pipe temps due to increased "burning down the pipe".
By allowing the burnt exhaust to be "left/added" to the new charge, it lowers NO2 emissions. This "leave some burnt mix" is one reason "smog" heads are so poor for "performance".
Also makes sense about the headers and the mixing of different cylinders. I have my WB 02 sensor (which also feeds a NB signal to the computer), in the #7 primary of my Hooker Super Comps. Originally I was told I needed to put it after the collector so I did. I couldn't get any part throttle readings that made any sense and the BLMS were all over the place. I moved it to the #7 primary after reading some threads on here and found that gives me the best readings but it still isn't like having the sensor in the combustion chamber.
I guess this is why trial and error as to what runs the best is better than any feedback from any sensors or gauges.
06-02-2009, 12:07 PM
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Re: WB-O2 results contradict BLMs
The spark plugs are our window into the combustion chamber.
It is like windage on a gun, aim where you have too to get the bullets to hit where you want.
Or skeet shooting, aim where the "pigeon" will be, not where it is at, or you will always be behind.
It is like windage on a gun, aim where you have too to get the bullets to hit where you want.
Or skeet shooting, aim where the "pigeon" will be, not where it is at, or you will always be behind.
06-02-2009, 04:47 PM
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Re: WB-O2 results contradict BLMs
I am running a LT1 style cam, so I should not have any significant overlap issues. As for the location of my WB and NB sensors: I am running Thorley Tri-Y headers. On the driver side I have my heated 3-wire NB just after the 2-into-1 collector, so it is picking up all 4 odd numbered cylinders. My WB is just in front of my catalytic after the main collator, so it is picking up all 8 cylinders.
Now to follow your discussion about combustion continuing through the header tube: Wouldn't that lead to a leaner reading further down the tube or do I have this backwards? In my case the WB is reading richer further down the exhaust system than the NB at all rpm/throttle positions.
Now to follow your discussion about combustion continuing through the header tube: Wouldn't that lead to a leaner reading further down the tube or do I have this backwards? In my case the WB is reading richer further down the exhaust system than the NB at all rpm/throttle positions.
06-02-2009, 07:49 PM
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Re: WB-O2 results contradict BLMs
Up the pipe would be more Oxygen (leaner) (before after burning) and down the pipe less Oxygen (richer) (after after burning).
A stock lean mix will leave more Oxygen unburnt (more O then fuel, fuel runs out first) and a rich mix will have less unburnt Oxygen (more Fuel then O, O runs out first). With a NB O2 0.0 volts is atmosphere (20% Oxygen) very lean and 1 volt is no Oxygen or very rich.
A WB is the opposite, 5 volts is atmosphere and 0.0 volts is no O.
Since the O2's, WB and NB, can't read the fuel (it is only an Oxygen sensor, right), it is predetermined that if there is Oxygen, then it is lean. Even if the O is mixed with a bunch of unburnt fuel (which in reality would be rich).
It is this assumption, that any oxygen left means all the fuel is gone, is the big lie. With a low overlap cam, you can assume that any Oxygen that is left, is there because the fuel is all gone. With a big overlap cam this is not true. This is the catch!
A stock lean mix will leave more Oxygen unburnt (more O then fuel, fuel runs out first) and a rich mix will have less unburnt Oxygen (more Fuel then O, O runs out first). With a NB O2 0.0 volts is atmosphere (20% Oxygen) very lean and 1 volt is no Oxygen or very rich.
A WB is the opposite, 5 volts is atmosphere and 0.0 volts is no O.
Since the O2's, WB and NB, can't read the fuel (it is only an Oxygen sensor, right), it is predetermined that if there is Oxygen, then it is lean. Even if the O is mixed with a bunch of unburnt fuel (which in reality would be rich).
It is this assumption, that any oxygen left means all the fuel is gone, is the big lie. With a low overlap cam, you can assume that any Oxygen that is left, is there because the fuel is all gone. With a big overlap cam this is not true. This is the catch!
06-05-2009, 07:04 PM
#28
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Re: WB-O2 results contradict BLMs
What effect would a consistant mis-fire have on the WBO2 and NBO2 readings given the location of my sensors above? I understand that a misfire will cause a lean reading. Is it possible that the WBO2 further down the exhaust system will show rich the the NB is false lean and the ECM is enriching the mixture?
I do sense a mis-fire in my motor. I will check out the sparkplugs, wires, and distributor this weekend.
I do sense a mis-fire in my motor. I will check out the sparkplugs, wires, and distributor this weekend.
06-06-2009, 01:08 PM
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Re: WB-O2 results contradict BLMs
Mis fire on NB O2 side of engine, reads lean because of extra oxygen from unburnt fuel/air. ECM will add more fuel to compenstate. WB will read rich because all 8 injectors are spraying more fuel.
Mis fire on opposite side of O2, all injectors will spray correct amount of fuel. The WB will read lean because of extra air from unburnt oxygen (mis fire). If there is enough mixing and it is hot enough to burn, the mixture may burn in the header/collector and give you a undetermined reading at the WB.
Mis fire on opposite side of O2, all injectors will spray correct amount of fuel. The WB will read lean because of extra air from unburnt oxygen (mis fire). If there is enough mixing and it is hot enough to burn, the mixture may burn in the header/collector and give you a undetermined reading at the WB.
06-06-2009, 09:13 PM
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Re: WB-O2 results contradict BLMs
Hopefully the missfire is now gone. I also found that the vacume line on the perge can was disconected. This seems to be a ported (is ported where there is no vacume at idel?) vacume line. Hopefully the combination of these 2 will fix my problem. I will get a chance to drive it tomorrow to find out.
thanks,
thanks,
06-07-2009, 07:35 AM
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Re: WB-O2 results contradict BLMs
Ported vacuum is a carb term and has to do with a hole (vacuum port) above the throttle blades. This only allows vacuum when the port is below the blades (off idle).
It was used to run the vacuum advance on smog engines. Most older engines used the maniflod vacuum directly.
The ECM controls the purge canister vacuum line with a solenoid, it is activated by conditions in the eprom cal and sensor inputs.
It was used to run the vacuum advance on smog engines. Most older engines used the maniflod vacuum directly.
The ECM controls the purge canister vacuum line with a solenoid, it is activated by conditions in the eprom cal and sensor inputs.
06-07-2009, 11:17 AM
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Re: WB-O2 results contradict BLMs
I have mine running from the canister (Driver side front) to the ported vacume on my TBI. On my application the ECM does not controll any solenoid, it is just straight ported vacume. I found the canister end of the vacume line was disconnected so I just had a large ported vacume leak. Hopefully this solves my problems.
thanks much, I really appreciate all the help!
Update:
I drove this morning and readings on the WBO2 did not change. With more thought, I do not suspect that a ported vacume leake will cause any problems as it is just additional air comming in that the ECM can account for (maybe I am wrong on this). I will keep plugging away.
thanks much, I really appreciate all the help!
Update:
I drove this morning and readings on the WBO2 did not change. With more thought, I do not suspect that a ported vacume leake will cause any problems as it is just additional air comming in that the ECM can account for (maybe I am wrong on this). I will keep plugging away.
Last edited by Keith91sub; 06-07-2009 at 01:49 PM.
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