tor1965
August 11th, 2010, 12:49 AM
After playing around with my tun I realize that tuning a pcm always are compromises between theory and practical experience. There are so many unknown factors in those operating systems that the easy theory seldom works out.
I am working on a 12212156 os that I am using on a stock ls3 engine. The engine runs and it has run a few hundreds kilometers this summer.
I started with a self made mix of ve tables and have used calc ve tuning and wideband to correct this table. The result is that more tuning and correcting, les sane values in the ve table. Obviously something is wrong. I have not trusted the wideband readings and now I have two new nb sensors and one new wideband sensor to be installed. Even then I don’t think this is the problem.
I also have a new used 411 pcm in the post somewhere. I need to eliminate every possible fault factors.
To build a correct ve table I feel that I need to start with correct injector flow data. I thought this was the easy part but not. The stock ls3 injector have bean used for several years with several application. I have got some tables from jocar and some other posted on the forum. First I thought that the ls3 had new injectors in 2010, and used some data from 2010 camaro because this was higher. The ve table upper part got fine but a bit to high. The lower part was way too high. Then I used the corvette values from jocar and that values gave to low readings in the upper portion and retained the same values in the lower part. My practical experience tells me that something is preventing the injector from give short enough opening time. Or less enough fuel. I have found a cax file for table b9021 and am going to test it.
The flow rates on the injectors are corrected by b3701 pulse width voltage adjustment. On the small ls1 injector this is about 0,4 ms at 14v. On the large ls3 injector this is about 0,7ms. This is a lot of fuel added on this big injector. How is this table handled in conjunction with the b4001 injector flow rate table? Is this correction also added to small pulse, (more then one pulse each stroke)?
When testing injectors. Are they stuck open for a longer period of time and the amount of fuel measured? And is this why we need a correction in b3701 at 14v, to imitate a duty cycle? Or are the injectors tested at different duty cycles and the B4001 average corrected for opening and closing time?
Can somebody please explain how this fuel injector tables in the 12212156 work together to give correct fuel flow numbers?
I am working on a 12212156 os that I am using on a stock ls3 engine. The engine runs and it has run a few hundreds kilometers this summer.
I started with a self made mix of ve tables and have used calc ve tuning and wideband to correct this table. The result is that more tuning and correcting, les sane values in the ve table. Obviously something is wrong. I have not trusted the wideband readings and now I have two new nb sensors and one new wideband sensor to be installed. Even then I don’t think this is the problem.
I also have a new used 411 pcm in the post somewhere. I need to eliminate every possible fault factors.
To build a correct ve table I feel that I need to start with correct injector flow data. I thought this was the easy part but not. The stock ls3 injector have bean used for several years with several application. I have got some tables from jocar and some other posted on the forum. First I thought that the ls3 had new injectors in 2010, and used some data from 2010 camaro because this was higher. The ve table upper part got fine but a bit to high. The lower part was way too high. Then I used the corvette values from jocar and that values gave to low readings in the upper portion and retained the same values in the lower part. My practical experience tells me that something is preventing the injector from give short enough opening time. Or less enough fuel. I have found a cax file for table b9021 and am going to test it.
The flow rates on the injectors are corrected by b3701 pulse width voltage adjustment. On the small ls1 injector this is about 0,4 ms at 14v. On the large ls3 injector this is about 0,7ms. This is a lot of fuel added on this big injector. How is this table handled in conjunction with the b4001 injector flow rate table? Is this correction also added to small pulse, (more then one pulse each stroke)?
When testing injectors. Are they stuck open for a longer period of time and the amount of fuel measured? And is this why we need a correction in b3701 at 14v, to imitate a duty cycle? Or are the injectors tested at different duty cycles and the B4001 average corrected for opening and closing time?
Can somebody please explain how this fuel injector tables in the 12212156 work together to give correct fuel flow numbers?