Is there a patch/hack to $8d to make the blm/int report while in open loop? If I go into closed loop, the ecm almost kills the car trying to correct it. I'd rather get it 'close enough' and stay in open loop. But I noticed in $8d, from a fresh power on (I disconnect my battery at night), it will set int/blm to 128 FOREVER while in open loop. I don't remember $58 behaving that way, but then again, when I ran $58 closed loop actually worked (smaller cam).

-- Joe

 

Not that I know of. But without looking I don't think it would be hard to add a BRA cmd using a hex editor. Look for the aujp hac on moates if you know a little hex and assembly. I'd help, but I'm a bit swamped lately with side work and other stuff.

 

It's supposed to be 128 in open loop. It uses closed loop to change BLM, so if you're clearing it (by disconnecting the battery), then how is it supposed to change if it's always in open loop???

 

I think he meant just to see it moving but not have it update anything.
Driving in OL and seeing what the change "would have been".
Not sure how possible that is in the code, haven't looked at it.

 

Thats exactly what I meant, heh.

-- Joe

 

Simply not possible if you stay open loop. BLM REQUIRES closed loop to even know what "would have been" is. It uses the O2 sensor and integrator to find stoich, and then BLM adapts to get integrator to 128. There's no way around that.

If you wanted, you could run in CL, learn some BLMs, then turn closed loop off. But, disconnecting the ECU will clear those BLMs, and often times, there's a calibration variable that limits the open loop BLM to a min and max of 128. Find those variables and change the limits, and DON'T disconnect the battery.

But, you simply can't use BLMs to tune without using closed loop. BLM is part of closed loop, it's not some super tuning part of the code that knows what correct is.

 

I forgot that the BLM is derived from NOT crossing a boundary after obtaining a previous boundary crossing. Without the first event, (if you managed to get it) the windup would go full scale forever.
Might be able to figure a correction value using the commanded AFR Vs. the WB input?? Disable CL in the code, store the value in an unused BLM cell and dump it out the ALDL.
Just thinking out loud.

 

The wideband seems nothing short of useless on a big cam. It will never read true afr with a cam with huge overlap. A lot of the guys on here that preach wb's have stock or small cams.

Also, theres no real magic afr to stick with. I was hoping to simply use BLM in open loop to "get it close" then tinker here, tinker there. Looks like I'll just have to do it how i've always done it.

I appreciate the feedback on the $8d code and blm. At least I can put that question to bed, and try something else.

-- Joe