Got fuel lined out with lc1 wideband, re enable fuel trims, it pulls 7 % goes lean
11-14-2009, 10:07 PM
#1
Got fuel lined out with lc1 wideband, re enable fuel trims, it pulls 7 % goes lean My friend has a 02 camaro that we were tuning tonight. The car has pacesetter long tubes, lid, ported tb, and no cats. He used the 13111 corvette rear 02 sensor as his primary 02 sensors, and his rears are deleted and the harness is under the car.
Tuning using hp tuners pro and an innovate lc1 wideband.
Now here is the problem.
We disabled fuel trims, disabled maf and dfco and everything and got the ve dialed in. Then re enabled everything and got the maf dialed in. Then turned back on fuel trims and this is when everything got strange. With everything plugged back in the ltft and stft immediately start pulling lots of fuel. They go -6 to -8 percent and the wideband reads high 15's to mid 16's.
Anyone have any ideas? I am wondering if maybe it is the 13111 corvette rear 02's being used as primary 02's might be causing it?
Any help would be greatly appreciated.
Oh, and another thing to add. I can watch the gauge on the laptop using the serial to usb converter, and the display on the laptop matches the one inside of hp tuners.
Tuning using hp tuners pro and an innovate lc1 wideband.
Now here is the problem.
We disabled fuel trims, disabled maf and dfco and everything and got the ve dialed in. Then re enabled everything and got the maf dialed in. Then turned back on fuel trims and this is when everything got strange. With everything plugged back in the ltft and stft immediately start pulling lots of fuel. They go -6 to -8 percent and the wideband reads high 15's to mid 16's.
Anyone have any ideas? I am wondering if maybe it is the 13111 corvette rear 02's being used as primary 02's might be causing it?
Any help would be greatly appreciated.
Oh, and another thing to add. I can watch the gauge on the laptop using the serial to usb converter, and the display on the laptop matches the one inside of hp tuners.
11-15-2009, 01:21 AM
#2
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Welcome to tuning.
What you have described has happened to a number of us.
If you are going by the wideband AFR and you trust its accuracy, then usually it is still due to inaccuracies in either the VE Table and or MAF. If you are trying to do a pure open-loop tune on the street, it is not always easy to get the same airflow values if your ECT, IAT, or BARO (elevation) change during the logging process.
Ultimately, you have to tune it the way you plan to run it. If you plan to remain closed-loop using Trims, as long as your O2's are healthy then you need to apply the Trim percentage differences against your MAF or VE Table depending on what type of tune you are running.
I would go back to the basics and make sure your injector data is accurate, wideband is working properly, and make sure you are getting an accurate base VE Table and/or MAF calibration.
Everybody has differing ideas, but I found more success staying closed-loop and 'tweaking' the initial airflow values from my VE Table and MAF values..using Trims.
Hope that makes sense. Believe me, I had the same experience. It is not always the fault of the narrowbands, but you can always try a fresh set to see if that is the problem. Sometimes it helps to keep you O2 Switch Points (Voltage) all one value when doing Trims. I.E., all 450-550 mv(s).
Good luck.
..WeathermanShawn..
What you have described has happened to a number of us.
If you are going by the wideband AFR and you trust its accuracy, then usually it is still due to inaccuracies in either the VE Table and or MAF. If you are trying to do a pure open-loop tune on the street, it is not always easy to get the same airflow values if your ECT, IAT, or BARO (elevation) change during the logging process.
Ultimately, you have to tune it the way you plan to run it. If you plan to remain closed-loop using Trims, as long as your O2's are healthy then you need to apply the Trim percentage differences against your MAF or VE Table depending on what type of tune you are running.
I would go back to the basics and make sure your injector data is accurate, wideband is working properly, and make sure you are getting an accurate base VE Table and/or MAF calibration.
Everybody has differing ideas, but I found more success staying closed-loop and 'tweaking' the initial airflow values from my VE Table and MAF values..using Trims.
Hope that makes sense. Believe me, I had the same experience. It is not always the fault of the narrowbands, but you can always try a fresh set to see if that is the problem. Sometimes it helps to keep you O2 Switch Points (Voltage) all one value when doing Trims. I.E., all 450-550 mv(s).
Good luck.
..WeathermanShawn..
11-15-2009, 07:32 AM
#3
Welcome to tuning.
What you have described has happened to a number of us.
If you are going by the wideband AFR and you trust its accuracy, then usually it is still due to inaccuracies in either the VE Table and or MAF. If you are trying to do a pure open-loop tune on the street, it is not always easy to get the same airflow values if your ECT, IAT, or BARO (elevation) change during the logging process.
Ultimately, you have to tune it the way you plan to run it. If you plan to remain closed-loop using Trims, as long as your O2's are healthy then you need to apply the Trim percentage differences against your MAF or VE Table depending on what type of tune you are running.
I would go back to the basics and make sure your injector data is accurate, wideband is working properly, and make sure you are getting an accurate base VE Table and/or MAF calibration.
Everybody has differing ideas, but I found more success staying closed-loop and 'tweaking' the initial airflow values from my VE Table and MAF values..using Trims.
Hope that makes sense. Believe me, I had the same experience. It is not always the fault of the narrowbands, but you can always try a fresh set to see if that is the problem. Sometimes it helps to keep you O2 Switch Points (Voltage) all one value when doing Trims. I.E., all 450-550 mv(s).
Good luck.
..WeathermanShawn..
What you have described has happened to a number of us.
If you are going by the wideband AFR and you trust its accuracy, then usually it is still due to inaccuracies in either the VE Table and or MAF. If you are trying to do a pure open-loop tune on the street, it is not always easy to get the same airflow values if your ECT, IAT, or BARO (elevation) change during the logging process.
Ultimately, you have to tune it the way you plan to run it. If you plan to remain closed-loop using Trims, as long as your O2's are healthy then you need to apply the Trim percentage differences against your MAF or VE Table depending on what type of tune you are running.
I would go back to the basics and make sure your injector data is accurate, wideband is working properly, and make sure you are getting an accurate base VE Table and/or MAF calibration.
Everybody has differing ideas, but I found more success staying closed-loop and 'tweaking' the initial airflow values from my VE Table and MAF values..using Trims.
Hope that makes sense. Believe me, I had the same experience. It is not always the fault of the narrowbands, but you can always try a fresh set to see if that is the problem. Sometimes it helps to keep you O2 Switch Points (Voltage) all one value when doing Trims. I.E., all 450-550 mv(s).
Good luck.
..WeathermanShawn..
We ended up turning off closed loop for the time being till we get things lined out.
At this point we are going to try swapping out the narrowband 02's and see what that does. Then the next step is maybe a pinhole around the wideband bung, or for some reason maybe it wasn't sealing all the way. We will try putting the wideband into the factory narrowband bung and see what that does. Past that I am stumped.
Attached is the tune where I turned back on ltft and stft and put everything back together and re enabled closed loop. Would you mind reviewing it and seeing if anything jumps out at you as being strange?
11-15-2009, 09:02 AM
#4
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if the error is only at idle rpm and low airflow. then it points to a small exhaust leak..
im having the same problem. gotta check the weld job on the wb o2 sensor
im having the same problem. gotta check the weld job on the wb o2 sensor
11-15-2009, 09:17 AM
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Hey Slammin:
I have the other premier tuning software suite, so I am unable to open HPT on my computer.
If someone with HPT might look it over, that would be great.
Sounds like you are on the right track. If you have Trims enabled, your Non-PE AFR's should be generally matching up to ~14.7 on your wideband.
I would work on the premise that either the wideband or narrowband O2 sensors are giving you inaccurate data. I also utilize the Corvette 13111 Rear O2 sensors as my Primaries (front O2's). Even with Headers I routinely stay closed-loop. I use 555 mv's as my O2 switch-points. Only occasionally at idle and low Rpm's do I get some 'wacky' O2 readings as compared to my wideband.
Good luck. I will follow your thread.
..WeathermanShawn..
I have the other premier tuning software suite, so I am unable to open HPT on my computer.
If someone with HPT might look it over, that would be great.
Sounds like you are on the right track. If you have Trims enabled, your Non-PE AFR's should be generally matching up to ~14.7 on your wideband.
I would work on the premise that either the wideband or narrowband O2 sensors are giving you inaccurate data. I also utilize the Corvette 13111 Rear O2 sensors as my Primaries (front O2's). Even with Headers I routinely stay closed-loop. I use 555 mv's as my O2 switch-points. Only occasionally at idle and low Rpm's do I get some 'wacky' O2 readings as compared to my wideband.
Good luck. I will follow your thread.
..WeathermanShawn..
11-16-2009, 08:43 AM
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Use the Narrowband 02s for tunning the VE. You dont get the voltage offset from the Wideband with the NB 02s. After all if you are going back to closed loop and the LTFTs and STFTs are what keep everything in line, Tunning with them will be more accurate for non PE fueling, for WOT use your wideband. Hope that helps
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12-10-2012, 06:23 PM
#8
TECH Fanatic
Is this whats got to be done for the wideband to keep the fuel in check? I hear there is a way for the wideband to keep the O2s in check at WOT! I really need to know how to do this.
