Tuning prob???
08-31-2014, 12:08 AM
#1
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Tuning prob??? I've got an LS6 on 12psi maggie. Just switched to the LS2 snout with the 90mm LS2 TB. It runs perfect up to around 5k but then completely bogs down like the butterfly closes? Does it every time with LS2 TB but never with the LS6 TB. I've tried two different LS2 throttle bodies and two separate adapter harnesses. No check engine lights or reduced power and the tuner says everything looks great on the tune. Only thing that was changed was ETC scaler I believe. What could possibly be causing this?
08-31-2014, 08:45 AM
#3
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In the DTC tab prior to the DTC list, there are DTC parameters for a few codes such as misfire etc. There is one DTC parameter that is set up like the VE map, this is the one that you have to adjust. I forget the DTC #, but it's the only one that looks like the VE map with throttle %.
08-31-2014, 01:53 PM
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He said it doesn't command it closed. It shows 100% and never changes at WOT .. Doesn't kill spark and doesn't even change the air fuel.
Also said missfire maxed.
Also said missfire maxed.
Last edited by jkel1124; 08-31-2014 at 03:42 PM.
08-31-2014, 09:54 PM
#5
:-)
Plz remove the intake tube and see for yourself that its open 100%.
A lot of times its not.
I am lost for words though. Maybe you just dont have enough guel pressure after 5k and its boggin...maybe your air filter isnt keepin up and its boggin
When was the last time, u changed the fuel filter, what type of airfilter u runnin
Plz remove the intake tube and see for yourself that its open 100%.
A lot of times its not.
I am lost for words though. Maybe you just dont have enough guel pressure after 5k and its boggin...maybe your air filter isnt keepin up and its boggin
When was the last time, u changed the fuel filter, what type of airfilter u runnin
08-31-2014, 10:52 PM
#6
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Volant CAI and Racetronix fuel system with new filter all less than 1000 miles. It almost feels like hitting the rev limiter, but no probs at all with the stock LS6 TB.
08-31-2014, 11:02 PM
#7
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In the DTC tab, go under Airflow and max out the P0106 DTC parameters and see if that changes anything for S&G's. What is your MAF freq when this occurs? I would log MAF freq with gram/cyl as you may be awefully close to the 512 gram/sec hard limit of the PCM which means youd have to scale.
The only thing that doesn't make sense is that you should have the same problem with the LS6 TB installed as well. Are you sure you have an LS2 TB? It has a silver blade, not gold, right?
If we could have a look at the tune we'd be much better equipped to assist.
If the PCM sees something it doesn't expect or understand it goes into limp mode. Most times there will be a DTC set, although mine has not set one a few times. You have to remember, we don't have access to all of the calibration data, so the PCM may be responding to something you cannot control directly and will have to work around, such as the 512 gram/sec hard limit which you have to scale the injectors as a work around.
The only thing that doesn't make sense is that you should have the same problem with the LS6 TB installed as well. Are you sure you have an LS2 TB? It has a silver blade, not gold, right?
If we could have a look at the tune we'd be much better equipped to assist.
If the PCM sees something it doesn't expect or understand it goes into limp mode. Most times there will be a DTC set, although mine has not set one a few times. You have to remember, we don't have access to all of the calibration data, so the PCM may be responding to something you cannot control directly and will have to work around, such as the 512 gram/sec hard limit which you have to scale the injectors as a work around.
Last edited by DMM; 08-31-2014 at 11:10 PM.
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09-01-2014, 12:43 AM
#10
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I'll forward this info to my tuner and maybe he can post the tune for you guys. It's definitely the LS2 TB with the silver blade...also tried a different one with exact same results. The Volant uses a k&n style filter that is supposed to flow well but I could just remove it to eliminate that as a possibility. I appreciate all the help and brainstorming.
09-15-2014, 03:58 PM
#16
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Had a quick look and here are a few things to go back on.
1. MAF calibration seems rather odd. Starts off really low and then maxes out the table value at 11,250 hz. Is this actual? Or, did the tuner get a reading and interpolate the remaining data? Either way, it just doesn't look correct. If high it should be high across the board, not low and then excessively high. You may need to step up to a larger MAF or (if the calibration data is correct) you're exceeding the hard limits of the PCM and you'd have to scale or go 2 BAR OS.
2. Injector data is wrong. It would appear you have 60 lb injectors however the data is incorrect. What type of injectors do you have?
3. Why was the O2 sensor balance point changed? Was it lean up top and tried to fatten up the fueling this way?
4. If you have a 160* T-stat there are a few tables that need to be adjusted so you're not fueling from the cold start enrichment tables during normal driving.
5. Spark retard was halved for some reason. Not a good idea.
6. VE map looks too "perfect" for lack of a better term. I've never seen a motor have that perfect of a VE map so I wonder if it was interpolated and smoothed just as the MAF calibration was.
7. The "P0106" Calculated MAP MAXIMUM is set to factory settings. Going by your VE map, you technically exceed this MAX limit at 3600 RPM.
I believe your problem is the P0106 calculated MAP maximum tables being set too low or you are hitting the 512/gram limit within the PCM.
Also, looking at your log you can see that everything is solid until about 4700 RPM and then it jumps up to 20* timing advance and goes to 23* before the throttle seems to slam shut (which happens in one frame). I'd be logging a lot more data. MAF wasn't even logged.
Hope that helped.
1. MAF calibration seems rather odd. Starts off really low and then maxes out the table value at 11,250 hz. Is this actual? Or, did the tuner get a reading and interpolate the remaining data? Either way, it just doesn't look correct. If high it should be high across the board, not low and then excessively high. You may need to step up to a larger MAF or (if the calibration data is correct) you're exceeding the hard limits of the PCM and you'd have to scale or go 2 BAR OS.
2. Injector data is wrong. It would appear you have 60 lb injectors however the data is incorrect. What type of injectors do you have?
3. Why was the O2 sensor balance point changed? Was it lean up top and tried to fatten up the fueling this way?
4. If you have a 160* T-stat there are a few tables that need to be adjusted so you're not fueling from the cold start enrichment tables during normal driving.
5. Spark retard was halved for some reason. Not a good idea.
6. VE map looks too "perfect" for lack of a better term. I've never seen a motor have that perfect of a VE map so I wonder if it was interpolated and smoothed just as the MAF calibration was.
7. The "P0106" Calculated MAP MAXIMUM is set to factory settings. Going by your VE map, you technically exceed this MAX limit at 3600 RPM.
I believe your problem is the P0106 calculated MAP maximum tables being set too low or you are hitting the 512/gram limit within the PCM.
Also, looking at your log you can see that everything is solid until about 4700 RPM and then it jumps up to 20* timing advance and goes to 23* before the throttle seems to slam shut (which happens in one frame). I'd be logging a lot more data. MAF wasn't even logged.
Hope that helped.
Last edited by DMM; 09-15-2014 at 04:07 PM.
09-15-2014, 09:14 PM
#18
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I honestly don't know how. I do t remember if that's something you can log. To make things worse, It could do a few things, shut down completely, keep fueling at the 512 gram/cyl level, or worst revert back to the first fueling cell which would be really bad.
If you run out of MAF hz you should theoretically keep fueling in PE mode, although it's not the best since you tecnically can no longer meter incoming air. You are maxing the MAF prior to running out of Hz, which is odd. I think the MAF and VE needs to be revisited first. If you can tell me what wide band your tuner is using I might be able to give them a much better PID to tune with.
If you run out of MAF hz you should theoretically keep fueling in PE mode, although it's not the best since you tecnically can no longer meter incoming air. You are maxing the MAF prior to running out of Hz, which is odd. I think the MAF and VE needs to be revisited first. If you can tell me what wide band your tuner is using I might be able to give them a much better PID to tune with.
09-15-2014, 09:29 PM
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I get it fuel pressure ruled out, only if fuel pressure remains constant true problem rpm. Check obstruction to fuel rails, even if fuel pressure remains constant will still starve.