Ok i just burned a new chip and this time i lowered all the numbers in my lower VE tables. Car runs much smoother at low rpm ,better on gas,better part throttle torque below like 2krpms, BUT i left everything above 3k rpms all the same as stock AUJP. NOW, i thought everything would be fine when driving over 3k rpms and WOT, but this isnt the case. This change to my lower VE Table seems to have effected the entire rpm range? WTF? I mean it runs very lean below 3k rpms which is what i suspected,but why is the entire operating range effected too?

 

Would be nice if you could elaborate a little more.

 

The main 3D VE table lookups are done by MAP and RPM. A VE cell at 1000 RPM will have no effect on a cell at 4000 RPM. The only time cells can impact eachother is when theyre adjacent, as the ECM interpolates between cells to provide a smooth output.

With that said, it would help to know what exactly it was that you altered. Also, how do you know its lean? Do you have a wideband?

 

Ok, i adjusted the lower VE tables with VE Master. Car IS leaner cause i am looking at the VE numbers which are lower than stock. Anything lower than stock numbers is leaner and anything higher than stock is richer. Also, i have been watching my BLM's and they are all over 128 now. That indicates leaner to me. The over all acceleration has changed in the car now. Seems like it takes longer to get to 4800 rpms now when accelerating at full throttle. Also, the car stumbles and feels like it is going to stall at idle now with the way the lower Ve Tables are now. It feels like it is getting just the mininum amount of fuel below 3k rpms now. Reminds me of when i lowered my fuel pressure down to 42psi one time. Car got way better mileage and ran much smoother at part throttle. Also, the engine temp is considerably hotter now. I suspect this due to running too lean. So, how should i really adjust my Ve tables? I am not sure what to add if i do it manually. Is there a formula to get my Blms close to 128 all the time? Please let me know cause i think VE Master is giving me numbers that are TOO lean.

 

If you dont have a WB O2, then theres really nothing you can gleen from the stock O2s and closed loop fueling at WOT. Theyre for part throttle only. The only way to tell if your truely lean is to use a wideband O2 and controller.

You can use the BLMs to tune part-throttle but thats about it.

 

"Is there a formula to get my Blms close to 128 all the time?"

post #6
https://www.thirdgen.org/forums/diy-...ttle-fuel.html

 

1.You had mentioned in post 4 you had lowered your fuel pressure at one time.
2.In your first post you had adjusted lower VE and got them right but it affected upper VE.

Is your BPC/BPW set correctly to fuel pressure, injector size and engine displacement?

The reason I ask is someone had mentioned adjusting their entire VE table by changing BPC/BPW and I knew it was wrong but have never tried, I always get BPC/BPW factored correctly to handle engine approx HP then tune VE. If I run out of fuel at WOT high RPM and have more then 95 VE I increase fuel pressure and re calculate BPC/BPW

So I tested their theory of adjusting BPC/BPW for an overall fueling change and the results were horrible! I increased BPC/BPW and lower VE went pig rich and upper VE went lean! You would expect both to do the same, but it is not the case. This was on a properly tuned engine with no changes to VE tables. Changin BPW/BPC back to proper setting and BLM numbers were back to 126 to 130 range across the RPM vs MAP table.

I don't know what is done to your engine but the first thing that needs to be set correctly before tuning any VE is BPC/BPW.

HTH!

 

jus buy a wideband ...

 

my fuel press. is at stock gm 43.5psi,injector constant set correctly.

 

where is the BPC/BPW adjustment in tunerpro?