Quote Originally Posted by spfautsch View Post
the wideband was flatlined at 0v (11.39:1) the entire 62 mile drive. .
It looks like a toast. Or it could be the controller. Are you running 4.2 or 4.9 bosch sensor. One of them was prone to early failures due to controller. I have 4.2 and it experienced alot of abusing[including coolant fouled and cleaned with acetone] and still works, not sure how acurate but it works. They should be pretty robust and last long since are oem used in turbo VAGs setup.



On the blm split. I am running different lenght tubes upto y and the sensors are at different lenght from the heads and still haven`t experienced heavy blm split. Actually they are pretty close off idle 2-4 points difference, with untuned off idle trims. At brief idle CL itempts I made I had 1-2 points only.


When you change settings look for at least 1 minute wait time for them to take effect, even changing the EOIT target takes some time, in the code there is smooth ramp out routine that makes it really slow.
If you find that there is a need for different target for idle and off idle vs rpm conditions, I will add the new tables in the code.

Spray pattern and lower than rated fuel pressure for the injectors could affect blms. Not sure how but I read somewhere that ls1 injectors had different spray pattern.

I have one theory how fuel robbing works. The path of the air is from the adjacent feed hole cylinder through the plenum, that way it can suck left over fuel. The path from other than adjacent cylinders will be too long for the fuel mix to travel. This effect can also lead to slowly filling the plenum with fuel vapors over time, making the mixture richer with longer idle events. Than can explain different behavour with supposedly prefectly tuned engine.

I didn`t get that deep in engine rotation, but if there are more than 1 cylinders sucking air at the same time like overlapping open intake valve events. Add to this the big cams overlap egr like effect, pushing small amounts of exhaust gas in the intake plenum and the picture gets worse.
If the cam you have opens the intake valve while the exhaust stroke upward cylinder movement is not finished, you are doomed for the perfect tune failure. Just get it close enough. You can always cure some blm splits with changing L and R swing voltages.

These are from stock ybody auto
L R
460.20 460.20
389.40 389.40
442.50 442.50
460.20 442.50
460.20 442.50

Vs stock ybody manual
L R
460.20 460.20
380.55 380.55
380.55 380.55
380.55 380.55
380.55 380.55