My tune has been running fairly well, but I do have a question about an issue:
When under heavy load (going up a hill etc), when the car enters WOT perameters, my Wide Band O2 consistantly shows 11.3 ish of AFR. My Bin is programed to be 12.8 AFR at WOT. Does this indicate that my Base Pulse Width Constant is set a bit high? Is there anything else to look at to get the WOT AFR to match what the BLM has as an input?

Thanks for the help,
Keith

 

Check the BLM variable. If it is greater then 128 it will be used during WOT which will add fuel. Otherwise it will be the VE table values that need to be changed.

RBob.

 

Is it not difficult to get a real BLM at that RPM/MAP unless PE is disabled? (not recommended).

would not you just drop appropriate VE fuel a little at a time until you see a desired A/F?

I had similar rich PE on WB that required I drop VE table values and then smoothen areas under accordingly.

If you learn from WB I believe you can get PE learns. Maybe I will try that this coming season.

 

Thanks, I don't learn for WB, I just look at the guage while driving. I will try adjusting the VE table. I was under the impression that the VE table was overridden when in PE mode, but I guess I was wrong. I do recall that BLM's were at 128 at WOT.
What effect does the WOT AFR table have if the VE table is used at that time?

 

When in PE mode the commanded AFR is changed. This affects the injector PW:

PW = BPC * ~AFR * ~T * VE * MAP

The ~ means inverse, a smaller value will make the PW larger. That is the basic PW equation.

RBob.

 

So a 118 BPW Constant is more fuel than a 134 BPW constant?

I guess what I should ask is what does the number stand for?

 

The Base Pulse Constant (BPC) is the ratio of engine displacement to injector flow rate rolled into one value. It is required for the speed density calculation of the required injector pulse width (PW).

A larger BPC will create a larger PW. Only the AFR and temperature (T) terms are inverse in the PW calculation.

RBob.

 

Thank You!