your data vs: mine.
..
Tried modified tune like said in PM.
Then added fuel in 5% increments just to check. Then logged each one.
Would not let me post last log.
In my mind it should not change lean to rich my just such a small amount of adjustment. I am starting to think it might be a hardware/mechanical issue instead of tune.
I have zeroed the Maf table and will try to adjust the cold start. Will try adjusted tune tomorrow. Getting late and need to go to bed. Plus think I might make my neighbors mad if I keep cranking the truck up this late. Thank You greatly for all of your help.
Here is the results of 0 Maf table and trying to get the VE as close as possible. Still have to use very small adjustments like changes of .5 to get it close and not rich or lean. Can't figure out why it is still doing this.
I have never had this motor setup be this sensitive to VE changes. The AFR%Error wants me to change say 20. But in reality if I change more than 1 it goes rich or lean. Are you thinking that it is my injector data causing this?
Found some one else having the same problem.
http://www.hptuners.com/forum/showthread.php?t=34600
Could a bad fuel pump cause this? I have not tested the pressure yet but will tomorrow after work. The reason I ask is it just seems odd that it ran fine on the wrong injector data for 200mi. Then it didn't run right after I parked it one day. Starting to look at other mechanical possibilities. Even with the wrong injector data it seems like it should not be this sensitive to tune.
You were right about not being a fuel pressure issue. The pressure is 52psi with vacuum and 60psi when I disconnect the vacuum hose. However, my gas smells really funny. It is not a sharp odor like I am use to kinda of a light fragrant smell. Will get some new/fresh gas this afternoon.
I believe you that the injector data is not right. Ran good on the data that was there for 200mi. However, since the issue started I have tried ever possible injector data that I could find in the repository for 42lb - 60lb injectors. All had the same result. I may send my injectors off to have them flowed and tested.
That vehicle has a vacuum referenced fuel pressure regulator, thus the IFR & Injector Offset table values are to be the same in all of the columns.
Russ Kemp
Pictures of my injectors.
The injectors I had that I posted above were mystery injectors that came with a TVS1900 kit. So I decided to get good injectors with known data. Okay, I have installed new LS3 injectors from Jon at FIC. Used known good LS3 data and plugged in the new IFC for these injectors. Seems several people have had good results with this combo. Example: (5 Liter Eater)
Still I have the same problem. Just can not get the darn thing to settle on a middle point between rich and lean. I am about to completely give up. It just doesn't seem to be worth it anymore. Please help me. How can I diagnose this problem. Nothing seems to be broken electrically or mechanically. Any comments or suggestions no matter how simple or complex would be welcome.
Current Tune
Let me make a list of what I have checked and tried.
1. All grounds are good: PCM, Battery to engine and body, both on back of the motor, and the one by the power steering pump.
2. Fuel pressure is 53psi with vacuum and 60psi without.
3. Not the injectors installed new ones from FIC with correct data.
4. New O2's went in with the motor 200mi and 2 weeks ago.
5. All coils are firing checked by way of cylinder drop test.
6. All input sensors are giving the HPT Scanner good readings.
7. Not a vacuum leak, smoked the intake system.