Fast O2 R/L threshold vs MAP
11-22-2015, 11:31 AM
#1
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Fast O2 R/L threshold vs MAP
So in my quest to get my calibration closer to the LT1 $DA3 calibration, I came across this again... and with my new wideband O2, I have a whole new level of visibility into what's going on with the engine and calibration...
So what I found is this...
The $DA3 version of this is Fast O2 R/L threshold vs Airflow (for left and right banks individually since it has dual O2's, although they're populated with the same values).
The curious thing is, in $8D, the thresholds (seemingly counter intuitively) gets leaner thresholds at higher MAPs.
Going from 20 to 100 kPa...
0.611
0.628
0.628
0.628
0.611
0.593
0.540
0.531
0.522
On the LT1 $DA3, it goes the opposite direction (which is what I would actually expect)
Going from 0 to 128 g/sec
460.2
531.0
566.4
601.8
610.6
I'm going to reverse the order on the 8D and see what happens (I'm still getting that part throttle lean condition that I was saying in my LSX injector offset thread, but the richening the MAT tables didn't solve it).
But my question is, what rationale would go into making the engine run leaner at higher MAP values? Emissions or something? Given how rich the factory 8D PE values are, I can't see how that would be the case...
So what I found is this...
The $DA3 version of this is Fast O2 R/L threshold vs Airflow (for left and right banks individually since it has dual O2's, although they're populated with the same values).
The curious thing is, in $8D, the thresholds (seemingly counter intuitively) gets leaner thresholds at higher MAPs.
Going from 20 to 100 kPa...
0.611
0.628
0.628
0.628
0.611
0.593
0.540
0.531
0.522
On the LT1 $DA3, it goes the opposite direction (which is what I would actually expect)
Going from 0 to 128 g/sec
460.2
531.0
566.4
601.8
610.6
I'm going to reverse the order on the 8D and see what happens (I'm still getting that part throttle lean condition that I was saying in my LSX injector offset thread, but the richening the MAT tables didn't solve it).
But my question is, what rationale would go into making the engine run leaner at higher MAP values? Emissions or something? Given how rich the factory 8D PE values are, I can't see how that would be the case...
Last edited by ULTM8Z; 11-22-2015 at 12:08 PM.
11-22-2015, 03:19 PM
#2
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Re: Fast O2 R/L threshold vs MAP
Hmmm.... reversing the order didn't seem to make that much difference...
Am I missing something else? BLM's and integrator don't seem to show a lean condition, but the wideband is reporting AFR's into the mid 16's on part throttle acceleration...
Am I missing something else? BLM's and integrator don't seem to show a lean condition, but the wideband is reporting AFR's into the mid 16's on part throttle acceleration...
11-22-2015, 05:54 PM
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Re: Fast O2 R/L threshold vs MAP
Can you eliminate the NBo2 as the culprit? I just had the opposite problem,lean BLM pig rich WBo2. New NBo2 solved problem.
11-23-2015, 12:16 PM
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Re: Fast O2 R/L threshold vs MAP
The Fast O2 R/L threshold table is used to count x-counts, reset the proportional gains, and to figure out whether the O2 is going in the lean(er) or rich(er) direction.
The two slow O2 tables (upper & lower) are used to define the target AFR.
RBob.
The two slow O2 tables (upper & lower) are used to define the target AFR.
RBob.
11-23-2015, 12:46 PM
#6
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Thread Starter
Re: Fast O2 R/L threshold vs MAP
Rbob, thanks for the info... I'll take a look at those tables.
On the fast O2, what does the ECM do with that x-count info once it gets it?
On the fast O2, what does the ECM do with that x-count info once it gets it?
11-25-2015, 11:40 AM
#7
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Re: Fast O2 R/L threshold vs MAP
Interesting...
When I look at the 8D calibration, there's a fairly wide spread between the Fast O2 R/L threshold values and the Slow O2 Upper and Lower zero error reference tables. Seems to be generating a operational window for each MAP value.
However, when I look at the DA3 code, the upper and lower zero error reference values are exactly equal to the Fast O2 values.
Is there some advantage to doing it the DA3 way? Maybe make the ECM respond faster to changes in the O2 sensor?
When I look at the 8D calibration, there's a fairly wide spread between the Fast O2 R/L threshold values and the Slow O2 Upper and Lower zero error reference tables. Seems to be generating a operational window for each MAP value.
However, when I look at the DA3 code, the upper and lower zero error reference values are exactly equal to the Fast O2 values.
Is there some advantage to doing it the DA3 way? Maybe make the ECM respond faster to changes in the O2 sensor?
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12-06-2015, 06:36 PM
#8
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Thread Starter
Re: Fast O2 R/L threshold vs MAP
Ok, color me stumped....
Did a few more things today and still haven't licked this lean-out condition...
1.) Changed fuel pump and filter - I got a high output pump (capable of 500+ hp)... figured I'd get it now since it'll feed my future small block 427... I don't remember when the filter was changed last, so I figured for ~10 bucks, I'd just rule it out.
2.) modified these Fast O2 R/L threshold tables every which way from Sunday... essentially no effect.
3.) It's not a part-throttle issue after all... I set the PE threshold to 20% to rule out the O2 sensor (basically a test to see if some the O2 was confusing the ECM somehow). But since the ECM ignores the O2 sensor in PE mode, it looks like that's not the case. I get the lean-out i PE or non-PE. BLM's are between 126 and 130 prior to entering PE.
4.) Kept an eye on the MAP sensor and TPS to see they were behaving strangely. It was rock solid at ~100 kPa at WOT. Despite going lean, it never dropped out of PE.
5.) I have the injectors pretty well dialed in at cruise and light throttle, just by playing with the injector constant and the getting offset vs battery voltage table correct. Nearly 128 everywhere and very nice feel to the throttle.
6.) I'm not getting any drop in fuel pressure... Even though I took a chance and changed the pump and filter, I was never getting a fuel pressure drop even at WOT. I guess that also probably rules out a restriction in the line some place too... If the injectors were flowing more fuel than the supply line could deliver I'd seen a noticeable pressure drop.
Any rate, what I"m finding is I have a commanded AFR of 13.21 above 3500 rpm, but the wide band (and I can actually feel the shuddering along with it) is reporting out over 16:1 and over, getting worse as RPM's go up. Above 3500 rpm, it just freaking leans out to the point where it feels like I'm hitting a rev limiter or something...
What the heck am I missing here?
Did a few more things today and still haven't licked this lean-out condition...
1.) Changed fuel pump and filter - I got a high output pump (capable of 500+ hp)... figured I'd get it now since it'll feed my future small block 427... I don't remember when the filter was changed last, so I figured for ~10 bucks, I'd just rule it out.
2.) modified these Fast O2 R/L threshold tables every which way from Sunday... essentially no effect.
3.) It's not a part-throttle issue after all... I set the PE threshold to 20% to rule out the O2 sensor (basically a test to see if some the O2 was confusing the ECM somehow). But since the ECM ignores the O2 sensor in PE mode, it looks like that's not the case. I get the lean-out i PE or non-PE. BLM's are between 126 and 130 prior to entering PE.
4.) Kept an eye on the MAP sensor and TPS to see they were behaving strangely. It was rock solid at ~100 kPa at WOT. Despite going lean, it never dropped out of PE.
5.) I have the injectors pretty well dialed in at cruise and light throttle, just by playing with the injector constant and the getting offset vs battery voltage table correct. Nearly 128 everywhere and very nice feel to the throttle.
6.) I'm not getting any drop in fuel pressure... Even though I took a chance and changed the pump and filter, I was never getting a fuel pressure drop even at WOT. I guess that also probably rules out a restriction in the line some place too... If the injectors were flowing more fuel than the supply line could deliver I'd seen a noticeable pressure drop.
Any rate, what I"m finding is I have a commanded AFR of 13.21 above 3500 rpm, but the wide band (and I can actually feel the shuddering along with it) is reporting out over 16:1 and over, getting worse as RPM's go up. Above 3500 rpm, it just freaking leans out to the point where it feels like I'm hitting a rev limiter or something...
What the heck am I missing here?
12-06-2015, 08:16 PM
#9
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Thread Starter
Re: Fast O2 R/L threshold vs MAP
Is this my problem? I don't seem to recall having this issue with my old 24 lb Fords, but I never had the wide band hooked up to it either...
https://www.thirdgen.org/forums/diy-...-above-3k.html
My tunerpro data says BPW is maxing out at 5.8 ms... Do I need to switch to S_AUJP now or something?
https://www.thirdgen.org/forums/diy-...-above-3k.html
My tunerpro data says BPW is maxing out at 5.8 ms... Do I need to switch to S_AUJP now or something?
Last edited by ULTM8Z; 12-06-2015 at 09:00 PM.
12-07-2015, 01:37 AM
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Re: Fast O2 R/L threshold vs MAP
Hard to understand how new injectors could be acting like they are restricted.
Data log says BPW maxed and WBo2 says lean then something is restricting flow.
It is hard to open a fuel system without getting some debris inside. I know the last thing you would want to do is open it up again, but just to eliminate the possibility of any debris in the system check the tiny filter baskets in the injectors. Hopefully none of these are missing. I did get a wrong filter once looked the same as the high pressure MPFI filter, but was for TBI no workie.
Just brain stormin for ya.
Data log says BPW maxed and WBo2 says lean then something is restricting flow.
It is hard to open a fuel system without getting some debris inside. I know the last thing you would want to do is open it up again, but just to eliminate the possibility of any debris in the system check the tiny filter baskets in the injectors. Hopefully none of these are missing. I did get a wrong filter once looked the same as the high pressure MPFI filter, but was for TBI no workie.
Just brain stormin for ya.
12-07-2015, 11:26 AM
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Re: Fast O2 R/L threshold vs MAP
Above 3,500 RPM I don't think your still in closed loop so those tables will not help.
If you are in CL, tables must be adjusted (all 3) together to keep the relationship correct.
RBob's explaination is in here too.
https://www.thirdgen.org/forums/diy-...ng-points.html
There is a spreadsheet I included in the S_AUJP package that shows how the tables relate to each other (you can graph changes too)
The coolant table is incorrect on the sheet as I have it in units it should be in "counts" but take a look anyway to see how they are laid out.
**************************
Does P.E. add the right fuel to get you down to ~12.5?
Get into the PE adder tables and jack them up until you see a response.
I don't think your PW is maxing out, appears it's being commanded to that level, need to command higher.
Increase PE Vs RPM table and see if it responds.
HTH
If you are in CL, tables must be adjusted (all 3) together to keep the relationship correct.
RBob's explaination is in here too.
https://www.thirdgen.org/forums/diy-...ng-points.html
There is a spreadsheet I included in the S_AUJP package that shows how the tables relate to each other (you can graph changes too)
The coolant table is incorrect on the sheet as I have it in units it should be in "counts" but take a look anyway to see how they are laid out.
**************************
Does P.E. add the right fuel to get you down to ~12.5?
Get into the PE adder tables and jack them up until you see a response.
I don't think your PW is maxing out, appears it's being commanded to that level, need to command higher.
Increase PE Vs RPM table and see if it responds.
HTH
12-07-2015, 12:18 PM
#12
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Thread Starter
Re: Fast O2 R/L threshold vs MAP
JP, I don't know if you read through the entire thread... posts 8 and 9 have pertinent info.
It does the same thing in both closed loop and PE.... The TP data indicates I'm getting a max BPW of about 5.8 ms.
After swapping injectors, I essentially disabled PE in order to get the VE’s dialed in. But then noticed it going super lean above 3500 while still in closed loop. So I started playing around with those Fast O2 threshold vs MAP tables…
I noticed the O2 threshold decreased with higher MAP in the factory ANHT code (which I thought was counterintuitive). So I reversed it such that the threshold goes up with MAP, in order to keep it richer at higher MAPs. I also took the upper and lower zero error reference tables along with it and kept their relationships the same relative to the nominal values as I adjusted the numbers (per what you’re saying). By the end of the testing, I had the O2 swing points up to .950 mV at higher MAPs, but it had no effect.
It was then suggested earlier in this thread to check the O2 sensor. But rather than buy another one, I figured I could rule it out by calibration. So yesterday I brought PE back online and lowered the TPS threshold to 20% to ensure I wasn’t in closed loop above 3500 rpm. The TunerPro data indicates I am in fact getting into PE. But the exact same lean condition exists…
I don’t think this is simply a minor discrepancy between commanded AFR and actual AFR that you’d see on a normally operating system… there appears to be something significantly wrong some place when I command 13:1 and I’m getting ~17.5:1 and higher with no drop in fuel pressure. By the time I hit 5000 rpm, the wideband essentially goes off the scale lean…
It does the same thing in both closed loop and PE.... The TP data indicates I'm getting a max BPW of about 5.8 ms.
After swapping injectors, I essentially disabled PE in order to get the VE’s dialed in. But then noticed it going super lean above 3500 while still in closed loop. So I started playing around with those Fast O2 threshold vs MAP tables…
I noticed the O2 threshold decreased with higher MAP in the factory ANHT code (which I thought was counterintuitive). So I reversed it such that the threshold goes up with MAP, in order to keep it richer at higher MAPs. I also took the upper and lower zero error reference tables along with it and kept their relationships the same relative to the nominal values as I adjusted the numbers (per what you’re saying). By the end of the testing, I had the O2 swing points up to .950 mV at higher MAPs, but it had no effect.
It was then suggested earlier in this thread to check the O2 sensor. But rather than buy another one, I figured I could rule it out by calibration. So yesterday I brought PE back online and lowered the TPS threshold to 20% to ensure I wasn’t in closed loop above 3500 rpm. The TunerPro data indicates I am in fact getting into PE. But the exact same lean condition exists…
I don’t think this is simply a minor discrepancy between commanded AFR and actual AFR that you’d see on a normally operating system… there appears to be something significantly wrong some place when I command 13:1 and I’m getting ~17.5:1 and higher with no drop in fuel pressure. By the time I hit 5000 rpm, the wideband essentially goes off the scale lean…
Last edited by ULTM8Z; 12-07-2015 at 12:33 PM.
12-10-2015, 01:40 PM
#13
Senior Member
Re: Fast O2 R/L threshold vs MAP
Realize it's been a while, but have been looking at this recently in the code. While o2 Cross-Counts are reported in the ALDL Data Stream as an indication of how fast sensor voltage is changing from going Rich to going Lean or vice-versa, they do not appear to be used during normal operation. Their occurrence is recorded by setting L003D b4. This bit then appears to only be used during o2 sensor testing in ALDL Diagnostics Mode with ALDL Pins A/B shorted and the engine running to blink-out a going rich or going lean condition.
01-30-2016, 09:33 PM
#14
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Re: Fast O2 R/L threshold vs MAP
Decided to revisit this after the AE TPS Filter Coefficient revisit went well...
I pretty much reversed the order of the values, such that the higher O2 thresholds at higher map values. Also reversed the upper and lower error thresholds.
Worked out nicely. While I'm not noticing a huge power increase or anything like that, nor do I really see a noticeable response on the WB. But what I'm noticing is what seems to be a better/smoother transition from closed loop into PE. Before you could kinda fell the "kick" when PE kicked in. Hard to describe, but it's definitely an improvement in "feel".
Anyway, this is pretty cool.... I'll have to go back in time and look for other things that gave me unexpected and/or ambiguous results before the Bosch III injector swap...
I pretty much reversed the order of the values, such that the higher O2 thresholds at higher map values. Also reversed the upper and lower error thresholds.
Worked out nicely. While I'm not noticing a huge power increase or anything like that, nor do I really see a noticeable response on the WB. But what I'm noticing is what seems to be a better/smoother transition from closed loop into PE. Before you could kinda fell the "kick" when PE kicked in. Hard to describe, but it's definitely an improvement in "feel".
Anyway, this is pretty cool.... I'll have to go back in time and look for other things that gave me unexpected and/or ambiguous results before the Bosch III injector swap...
01-31-2016, 03:33 PM
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Re: Fast O2 R/L threshold vs MAP
I read what is happening but fail to see how the filters, AE (TPS or MAP) will cap your PW and go lean continuously. They would be tip in, or transitional.
The PW cap is more prone to higher CID so may not be playing a role.
(The O2 table info was for reference to show how they related over RPM if you wanted to look into them)
For the current problem,
There must be a commanded level in the PE tables that could drive your AFR down to 10 if desired. I don't recall that many items that can limit the amount of fuel in PE when directly commanded.
Sounds like you can not get that to happen under any circumstances.
Could your voltage be low or injector compensations be incorrect?
Injectors could be commanded but are just not opening with enough speed and the comp tables are not enough?
The PW cap is more prone to higher CID so may not be playing a role.
(The O2 table info was for reference to show how they related over RPM if you wanted to look into them)
For the current problem,
There must be a commanded level in the PE tables that could drive your AFR down to 10 if desired. I don't recall that many items that can limit the amount of fuel in PE when directly commanded.
Sounds like you can not get that to happen under any circumstances.
Could your voltage be low or injector compensations be incorrect?
Injectors could be commanded but are just not opening with enough speed and the comp tables are not enough?
01-31-2016, 05:10 PM
#16
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Re: Fast O2 R/L threshold vs MAP
JP, I've already conquered the PE AFR issue. Basically I command something on the order of 12:1 in order to get 13:2 at the WB.
I simply replied to this earlier thread since it was already discussing the Fast O2 R/L tables (rather than opening a new thread on the subject).
I simply replied to this earlier thread since it was already discussing the Fast O2 R/L tables (rather than opening a new thread on the subject).
01-14-2017, 11:38 PM
#17
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Re: Fast O2 R/L threshold vs MAP
Got the car back on the road the other week after about a year (transmission debacle....long story....)
But, I'm finding that the part throttle lean condition is still occurring...
I cruise at a nice 14.5-15:1 in the mid-range, which is great.
But if I get into the throttle a little (not quite into PE), the AFR starts getting up into the 16's... Not sure what to do to get it back down... I'd like to see mid 13's to low 14's for that. As stated in an earlier post above, I the PE AFR licked... it's right where I want it. This is now all about AFR in part throttle.
I've played around with the Fast O2 vs MAP as well as the tables for upper and lower zero error reference for slow 2 vs MAP. I've also lowered the Stoich value to 14.0 and none of this seems to have an effect.
I know the integrator isn't indicating it's chasing a lean condition... it seems like the ECM somehow thinks this is normal?? How do I tell it I want the AFR richer?
There's a table Slow O2 Filter Coefficient vs Airflow, but I don't know what it does...
If I increase the VE tables, the integrator is just going to pull fuel back out...
But, I'm finding that the part throttle lean condition is still occurring...
I cruise at a nice 14.5-15:1 in the mid-range, which is great.
But if I get into the throttle a little (not quite into PE), the AFR starts getting up into the 16's... Not sure what to do to get it back down... I'd like to see mid 13's to low 14's for that. As stated in an earlier post above, I the PE AFR licked... it's right where I want it. This is now all about AFR in part throttle.
I've played around with the Fast O2 vs MAP as well as the tables for upper and lower zero error reference for slow 2 vs MAP. I've also lowered the Stoich value to 14.0 and none of this seems to have an effect.
I know the integrator isn't indicating it's chasing a lean condition... it seems like the ECM somehow thinks this is normal?? How do I tell it I want the AFR richer?
There's a table Slow O2 Filter Coefficient vs Airflow, but I don't know what it does...
If I increase the VE tables, the integrator is just going to pull fuel back out...
01-17-2017, 08:01 PM
#18
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Re: Fast O2 R/L threshold vs MAP
Anyone have any thoughts? Just trying to see what **** to turn to get the AFR out of the 15-16's during part throttle (non-WOT) acceleration... the Integrator seems to stay in the 124 to 134 range during the time I'm seeing the 15-16 AFR... So for whatever reason, the computer seems to think this is good.
When I first start the car (when it's still warmed up) and take off in open loop, the throttle feels much better (AFR showing in the 13-14 range). Soon as it goes into closed loop, the ECM seems to be pulling fuel out.
BTW, the car idles at around 13.5 to 14:1 which it seems to like.
So glad I got this WB O2 sensor... wouldn't have known any of this was going on without it...
When I first start the car (when it's still warmed up) and take off in open loop, the throttle feels much better (AFR showing in the 13-14 range). Soon as it goes into closed loop, the ECM seems to be pulling fuel out.
BTW, the car idles at around 13.5 to 14:1 which it seems to like.
So glad I got this WB O2 sensor... wouldn't have known any of this was going on without it...
Last edited by ULTM8Z; 01-17-2017 at 08:49 PM.
01-18-2017, 05:40 AM
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Re: Fast O2 R/L threshold vs MAP
Good to have you back, I'm still chasing the same ghost you are. In my case I'm just about convinced it's a reversion issue with the mini ram. I'll be listening.
01-18-2017, 08:02 AM
#20
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Re: Fast O2 R/L threshold vs MAP
I guess I'm not ready to chalk it up to the manifold design just yet... I had thought the AE was un-tunable with the Miniram until I finally uncovered the issue with the injector voltage offsets, at which point the AE became MUCH easier to tune for and I have it damn near perfect now.
What leads me to believe I'm fighting some sort of closed loop calibration issue is the fact that the car runs "the way it should" during open loop (just before going into closed loop).
What leads me to believe I'm fighting some sort of closed loop calibration issue is the fact that the car runs "the way it should" during open loop (just before going into closed loop).
01-18-2017, 09:16 AM
#21
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Re: Fast O2 R/L threshold vs MAP
Maybe the NB O2 sensor is silicone poisoned. I take it that the engine sputters when it gets lean?
RBob.
RBob.
01-18-2017, 03:40 PM
#22
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Re: Fast O2 R/L threshold vs MAP
No sputtering. If it gets to the high 16s I'll detect a slight hesitation.
I believe I swapped o2 sensors earlier on last year... guess I'll do that again just to be sure.
I believe I swapped o2 sensors earlier on last year... guess I'll do that again just to be sure.
01-18-2017, 06:56 PM
#23
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Re: Fast O2 R/L threshold vs MAP
Too much SA at that point can cause hesitation and show lean even if it is not lean. Detonation is not the only sign of too much advance.