Running way to lean in cold open loop. How do I fix it?
Yrs, the increased overlap in the cam will most certainly read lean on the widebands at idle. Don't be to worried about the idle performance. If you don't have engough fuel down there, it will just misfire. You will know when you have too much when you hit the throttle and nothing but black comes out. You can pm me with any questions. I have done a couple of sprint cars, 1 running a 6.2L and the other running a 7.0L. If you want to know what it is like to get something with no flywheel mass to idle, just let me know.
Another consideration is the injectors. If you do feel that it is lean, you are going to have to increase your minimum injector on time and add the correct values to the ow pulse width on time table. What happens is with big injectors, they cannot respond fast enough at low pulsewidths and will just simply not open everytime. This sucks to deal with, but once you figure that out, it is easy to get around it.
Another consideration is the injectors. If you do feel that it is lean, you are going to have to increase your minimum injector on time and add the correct values to the ow pulse width on time table. What happens is with big injectors, they cannot respond fast enough at low pulsewidths and will just simply not open everytime. This sucks to deal with, but once you figure that out, it is easy to get around it.
Yrs, the increased overlap in the cam will most certainly read lean on the widebands at idle. Don't be to worried about the idle performance. If you don't have engough fuel down there, it will just misfire. You will know when you have too much when you hit the throttle and nothing but black comes out. You can pm me with any questions. I have done a couple of sprint cars, 1 running a 6.2L and the other running a 7.0L. If you want to know what it is like to get something with no flywheel mass to idle, just let me know.
Another consideration is the injectors. If you do feel that it is lean, you are going to have to increase your minimum injector on time and add the correct values to the ow pulse width on time table. What happens is with big injectors, they cannot respond fast enough at low pulsewidths and will just simply not open everytime. This sucks to deal with, but once you figure that out, it is easy to get around it.
Another consideration is the injectors. If you do feel that it is lean, you are going to have to increase your minimum injector on time and add the correct values to the ow pulse width on time table. What happens is with big injectors, they cannot respond fast enough at low pulsewidths and will just simply not open everytime. This sucks to deal with, but once you figure that out, it is easy to get around it.
I redid some of his tune to get him started. From there he should be able to tune the VE and get it dialed in.
From monitoring EFI-Live's forums I have found not every variable is used by GM in a particular OS.
I am def going to try that myself.
Ed is helping me fix this but I want to understand why it was doing this?
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
Thanks
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
Thanks
Last edited by 1Hotbird; Dec 26, 2007 at 06:33 PM.
Let's talk about this graph of the VE and what it means.
Figure 1: Raw difference from Stock VE compared to your modified VE.
Each of these cells represents the difference ( Modified - Stock). Not %. Just raw difference. The stock file was from www.holdencrazy.com. This is generated by loading the stock tune for comparison vs your tune in EFI-Live.
What looks wrong is the raw difference is flat. It is more than stock but entirely flat. They couldn't of tuned cell by cell and ended up with the same shape if you did heads and enlarged your bore. Just not possible. Given that... I believe what they programmed could never match the true demands of your engine....besides your cold start up problems.
Because the VE isn't correct even if you put in the correct AFR it still can't generate that AFR. That is why you are ok at idle and lean under load. Those heads surely flow more under load than stock so I don't think a flat adjustment to the VE table will work!
------------------------
Have you loaded up the file provided by Ed and has it helped? With the corrected AFR table, displacement, and VE you should be much closer. I believe you will not be able to resolve all your problems with only one thread. So don't worry.
Figure 1: Raw difference from Stock VE compared to your modified VE.
Each of these cells represents the difference ( Modified - Stock). Not %. Just raw difference. The stock file was from www.holdencrazy.com. This is generated by loading the stock tune for comparison vs your tune in EFI-Live.
What looks wrong is the raw difference is flat. It is more than stock but entirely flat. They couldn't of tuned cell by cell and ended up with the same shape if you did heads and enlarged your bore. Just not possible. Given that... I believe what they programmed could never match the true demands of your engine....besides your cold start up problems.
Because the VE isn't correct even if you put in the correct AFR it still can't generate that AFR. That is why you are ok at idle and lean under load. Those heads surely flow more under load than stock so I don't think a flat adjustment to the VE table will work!
------------------------
Have you loaded up the file provided by Ed and has it helped? With the corrected AFR table, displacement, and VE you should be much closer. I believe you will not be able to resolve all your problems with only one thread. So don't worry.
Last edited by 2002_Z28_Six_Speed; Dec 27, 2007 at 03:58 PM.
Ok I think its safe to say that the ve table was not tuned properly.
I need to tune the ve. it looks to me like he changed the whole ve table by a percentage. Still no one has a answer for my original question?
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
I need to tune the ve. it looks to me like he changed the whole ve table by a percentage. Still no one has a answer for my original question?
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
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Verdad Gallardo I will post the tunes and logs If its ok With Ed.
Last edited by 1Hotbird; Dec 27, 2007 at 10:28 PM.
Ok I think its safe to say that the ve table was not tuned properly.
I need to tune the ve. it looks to me like he changed the whole ve table by a percentage. Still no one has a answer for my original question?
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
I need to tune the ve. it looks to me like he changed the whole ve table by a percentage. Still no one has a answer for my original question?
If it gets all the command fuel ratio from the cold open loop table, the why was it not running lean with no throttle?
At idle I have 14.xx fuel ratio and part throttle It would jump to 18.xx-20.xx???
Because that OL fuel table is based on the VE table, those numbers are VE multipliers. If the VE is off, then you won't get commanded fueling. I bet your PE table was jacked up too since the VE was near stock. It was a cheat on the numbers. If in OL table (or PE) and you have to command 1.2 (about 12.2:1) to get 14.6-7 (should be commanding 1 if the VE was right), that shows that the underlying VE cell(s) are off by about 20%, since that is the amount the value was "cheated" to achieve desired AFR.
So if I command a 12.2 (1.2) it multiplys the ve by 1.2?? Do I understand that correctly?
Say the ve # is 20 To command a 14.63(1) it would use 20??
Say the ve # is 20 To command a 12.2 (1.2) it would use 24??
Is this correct??
In your case (SD), close enough to say yes, but you never see those numbers. I don't know EFIL's scanner, but you can log equiv ratio, that is the final commanded fueling (unless you are in closed loop). HPT has a canned PID for commanded AFR, which is stoich/equiv and I'm sure with your auto-VE that EFIL has the same. I would be careful using auto VE around idle until you get a feel for how your overlap has affected your observed vs. real AFR... though again, I haven't used it, but the "manual" process works the same. Just listen to whatever Ed has told ya 
Last edited by Frost; Dec 27, 2007 at 10:28 PM.
In your case (SD), close enough to say yes, but you never see those numbers. I don't know EFIL's scanner, but you can log equiv ratio, that is the final commanded fueling (unless you are in closed loop). HPT has a canned PID for commanded AFR, which is stoich/equiv and I'm sure with your auto-VE that EFIL has the same. I would be careful using auto VE around idle until you get a feel for how your overlap is affected your observed vs. real AFR... though again, I haven't used it, but the "manual" process works the same. Just listen to whatever Ed has told ya
I dont mind if you post up the tune I sent you. Its just a base line to get ya goin.
BTW, you still have the MAF enabled, so you really arent tuning in SD yet. You'll need to disable that and then dial in the VE.
As for Auto VE and idle, you may have to play with the VE values at idle to get it to idle nice, and not worry about the WB readings.
As far as PE and its effect on A/F, you shouldnt even be worrying about that right now, as while tuning the VE you should be staying out of PE. You may want to set the eq, ratio to 1 up to like 4000, and/or set the TPS enable to 100% up to around 4000, that way it has no effect while you're tuning the VE.
BTW, you still have the MAF enabled, so you really arent tuning in SD yet. You'll need to disable that and then dial in the VE.
As for Auto VE and idle, you may have to play with the VE values at idle to get it to idle nice, and not worry about the WB readings.
As far as PE and its effect on A/F, you shouldnt even be worrying about that right now, as while tuning the VE you should be staying out of PE. You may want to set the eq, ratio to 1 up to like 4000, and/or set the TPS enable to 100% up to around 4000, that way it has no effect while you're tuning the VE.
Let's talk about this graph of the VE and what it means.
Figure 1: Raw difference from Stock VE compared to your modified VE.
Each of these cells represents the difference ( Modified - Stock). Not %. Just raw difference. The stock file was from www.holdencrazy.com. This is generated by loading the stock tune for comparison vs your tune in EFI-Live.
What looks wrong is the raw difference is flat. It is more than stock but entirely flat. They couldn't of tuned cell by cell and ended up with the same shape if you did heads and enlarged your bore. Just not possible. Given that... I believe what they programmed could never match the true demands of your engine....besides your cold start up problems.
Because the VE isn't correct even if you put in the correct AFR it still can't generate that AFR. That is why you are ok at idle and lean under load. Those heads surely flow more under load than stock so I don't think a flat adjustment to the VE table will work!
------------------------
Have you loaded up the file provided by Ed and has it helped? With the corrected AFR table, displacement, and VE you should be much closer. I believe you will not be able to resolve all your problems with only one thread. So don't worry.
Figure 1: Raw difference from Stock VE compared to your modified VE.
Each of these cells represents the difference ( Modified - Stock). Not %. Just raw difference. The stock file was from www.holdencrazy.com. This is generated by loading the stock tune for comparison vs your tune in EFI-Live.
What looks wrong is the raw difference is flat. It is more than stock but entirely flat. They couldn't of tuned cell by cell and ended up with the same shape if you did heads and enlarged your bore. Just not possible. Given that... I believe what they programmed could never match the true demands of your engine....besides your cold start up problems.
Because the VE isn't correct even if you put in the correct AFR it still can't generate that AFR. That is why you are ok at idle and lean under load. Those heads surely flow more under load than stock so I don't think a flat adjustment to the VE table will work!
------------------------
Have you loaded up the file provided by Ed and has it helped? With the corrected AFR table, displacement, and VE you should be much closer. I believe you will not be able to resolve all your problems with only one thread. So don't worry.
The funny thing was, the 2 VE table were different, but neither one was close to being right.
I dont mind if you post up the tune I sent you. Its just a base line to get ya goin.
BTW, you still have the MAF enabled, so you really arent tuning in SD yet. You'll need to disable that and then dial in the VE.
As for Auto VE and idle, you may have to play with the VE values at idle to get it to idle nice, and not worry about the WB readings.
As far as PE and its effect on A/F, you shouldnt even be worrying about that right now, as while tuning the VE you should be staying out of PE. You may want to set the eq, ratio to 1 up to like 4000, and/or set the TPS enable to 100% up to around 4000, that way it has no effect while you're tuning the VE.
BTW, you still have the MAF enabled, so you really arent tuning in SD yet. You'll need to disable that and then dial in the VE.
As for Auto VE and idle, you may have to play with the VE values at idle to get it to idle nice, and not worry about the WB readings.
As far as PE and its effect on A/F, you shouldnt even be worrying about that right now, as while tuning the VE you should be staying out of PE. You may want to set the eq, ratio to 1 up to like 4000, and/or set the TPS enable to 100% up to around 4000, that way it has no effect while you're tuning the VE.
Yeah, I realize his VE was stock, even if he doesnt/didnt. I set the lower rpm stuff so it wouldnt gag on fuel, and left the rest alone for him to tune via auto VE, or just logging with his charts/histograms.
The funny thing was, the 2 VE table were different, but neither one was close to being right.
The funny thing was, the 2 VE table were different, but neither one was close to being right.
Oh. I wasn't targeting you as I have no doubts about your tuning abilities. It was just a generic explanation of why the car was behaving as it is.
I subsequently set up a SD tune, so he could go out and start to dial in the VE.
Ok I think I understand tuning the ve table by wideband and fuel trims. I can't ve tune it till spring but I still want to learn how to keep going. So how Do I go about tuning the Maf??
Whats the proper order to tune it in??
Setup injectors, Ve table, Maf, spark, ????????
Whats the proper order to tune it in??
Setup injectors, Ve table, Maf, spark, ????????
I put those injectors on a bone stock 347 just to get them tuned in before putting on the turbo. I can't even imagine any way in hell they would be difficult to tune on a 454.