Open Loop BLM?????

[ralmo94]

The 250 file in post #13 is a .adx file for data logging.

The 251 is a .xdf file for editing the .bin file file.

The gearhead-efi link for $OD information: http://www.gearhead-efi.com/Fuel-Inj...Information-0D

From 1project2many:
Corrected Advanced $0D TP5 v251 Low Async Short BPW Offset vs. BPW table to correctly use Async Short BPW Offset Bias. New version uploaded as Advanced $0D TP5 v251.xdf .

dave w

Ok. Thanks. Silly me I didn't look at the file extension. That link is the page I got all files from I started with. BCC code on pcm was BJLF. I switched to BJLH, as a diagnosis on other issue that has since been figured out. Since I had fixed the problem I was having with the BJLH bin, I didn't revert back to LF.

[ralmo94]

i've never used $0D but pretty sure $0D actually stores them in eeprom or something so removing battery power will not work. there should be some blm keep-alive settings in the bin you can modify to control the range of values that are stored. you can probably clear them via the datastream, doesnt your ADX have something for that?

Can someone confirm on the correct way to clear BLM ( fuel trims) on a 7427 series $OD.

I know I'm not the first to tune $OD. Before I went open loop, disconnecting battery seamed to work.

[1project2many]

It appears Scantool can clear BLM through mode 4 request
Status bit b4 @ $0045 can also initiate BLM reset.
Among other things, BLM will not change if INT is not outside window.
Even if BLM is changing, BLM will be clamped to max and min values per following code:

BLM clamp routine
;
;~~~~~~~~~~~~~~~~~~~~~
;
LEF2B	LDAA    L48F3			;Upper limit for BLMs
	LDAB    L48F4			;Lower limit for BLMs
;
	LDX     #L02D6			;Addr of first BLM cell
LEF34	CMPA    0,X			;Compare upper lim. to BLM
	BCC     LEF3A			;Bra if BLM less
;
	STAA    0,X			;Save upper limit instead
;
LEF3A	CMPB    0,X			;Compare lower lim. to BLM
	BLS     LEF40			;Bra if lower limit is less
;
	STAB    0,X			;Save lower limit instead
;
LEF40   INX				;+1, advance to next cell
	CPX     #L02EA			;Last BLM cell
	BLS     LEF34			;Bra if not at last cell yet, continue
;
	RTS  				;Return

This means that setting max and min BLM to 128 will cause ECM to check all 16 BLM cells to ensure they are between 128 and 128. If BLM in a cell is found to be outside the range then it is set to the limit instead, in this case 128.

[ralmo94]

It appears Scantool can clear BLM through mode 4 request
Status bit b4 @ $0045 can also initiate BLM reset.
Among other things, BLM will not change if INT is not outside window.
Even if BLM is changing, BLM will be clamped to max and min values per following code:

BLM clamp routine
;
;~~~~~~~~~~~~~~~~~~~~~
;
LEF2B	LDAA    L48F3			;Upper limit for BLMs
	LDAB    L48F4			;Lower limit for BLMs
;
	LDX     #L02D6			;Addr of first BLM cell
LEF34	CMPA    0,X			;Compare upper lim. to BLM
	BCC     LEF3A			;Bra if BLM less
;
	STAA    0,X			;Save upper limit instead
;
LEF3A	CMPB    0,X			;Compare lower lim. to BLM
	BLS     LEF40			;Bra if lower limit is less
;
	STAB    0,X			;Save lower limit instead
;
LEF40   INX				;+1, advance to next cell
	CPX     #L02EA			;Last BLM cell
	BLS     LEF34			;Bra if not at last cell yet, continue
;
	RTS  				;Return

This means that setting max and min BLM to 128 will cause ECM to check all 16 BLM cells to ensure they are between 128 and 128. If BLM in a cell is found to be outside the range then it is set to the limit instead, in this case 128.

I don't really understand everything you said

The last statement and the first statement I understand. I don't have a scan tool for OBD1. I don't know what "status bit b4" is. Is that in tuner pro?

I Really appreciate the all the code, but kinda feels like I'm a little kid looking for pictures in a book. LOL

I am guessing that the general jist of that is that I should be fine with what I attempted to fix.
07/12/2020 20:38:36 Scalar: Minimum BLM changed from 105 BLM (0x69) to 128 BLM (0x80).
07/12/2020 20:38:49 Scalar: Minimum BLM at Idle changed from 90 BLM (0x5A) to 128 BLM (0x80).
07/12/2020 20:38:56 Scalar: BLM Step Value changed from 1 BLM (0x01) to 0 BLM (0x00).
07/12/2020 20:39:06 Scalar: Maximum BLM changed from 165 BLM (0xA5) to 128 BLM (0x80).
07/12/2020 20:39:14 Scalar: Maximum Initial BLM changed from 135 BLM (0x87) to 128 BLM (0x80).
07/12/2020 20:39:24 Scalar: Minimum Initial BLM changed from 126 BLM (0x7E) to 128 BLM (0x80).

After my laptop charged, I got a data log, and unhooking battery seemed to clear BLM's, as they stayed at 128 for the whole log. But if there is a way to use tunerpro rt, I am all ears.

Thank You

[1project2many]

That's ok. Being able to read code is a benefit to what you're doing but not a requirement. But other folks helping can read code and may be able to add information based on what I posted.

The names of the limits that you posted do not exactly correlate with the code I posted. That's ok. The next step is to evaluate the XDF definition to see if any of the limits you've adjusted are located at the addresses called out in the code. Namely, 0x48F3 and 0x48F4. If you have set both of those limits to 128 then it appears the code should repeatedly reset BLM to 128.

You can "edit XDF parameter" in Tunerpro to see what location in the chip you are changing. I think an explanation would take more time than I have now. I will try to post some information to help tonight. I will also look at the .xdf you posted.

[ralmo94]

That's ok. Being able to read code is a benefit to what you're doing but not a requirement. But other folks helping can read code and may be able to add information based on what I posted.

The names of the limits that you posted do not exactly correlate with the code I posted. That's ok. The next step is to evaluate the XDF definition to see if any of the limits you've adjusted are located at the addresses called out in the code. Namely, 0x48F3 and 0x48F4. If you have set both of those limits to 128 then it appears the code should repeatedly reset BLM to 128.

You can "edit XDF parameter" in Tunerpro to see what location in the chip you are changing. I think an explanation would take more time than I have now. I will try to post some information to help tonight. I will also look at the .xdf you posted.

Thank You!!! Looks like the addresses you posted go to the min and max initial BLM.

So if I understand the code correctly, If initial BLM is capped at 128, the code doesn't go any further?

[1project2many]

So if I understand the code correctly, If initial BLM is capped at 128, the code doesn't go any further?

First, my apologies for not getting back to this sooner.

That section of code will "reset" every BLM cell keeping them within the window defined by the Initial BLM limits. There is another section of code which will reset code to 128 as well. Reading code accurately can take more than a brief look so if you are still seeing BLM change even though the Initial BLM's are set to 128 I will have to look further into how the code operates.

[ralmo94]

Thank you. Don't seem to have any BLM after changing the fields mentioned. My VE is pretty close now to. Last data log most cells within 3%. Now shooting for within 3% all on rich side. Is that what most aim for to call it done? I am planning on remaining open loop.

[dave w]

I'm hoping to learn and understand what the tuning expectations and / or ultimate tuning results will be accomplished with resetting the BLM's?

I'm understanding the desired goal to successfully tune open loop only, but I'm thinking it is not necessary to reset BLM's to successfully tune open loop?

Have you tried tuning open loop with the Open Loop AFR vs. Temperature vs. Vacuum table? I tune closed loop, but to I still need to adjust open loop choke AFR's and open loop warm up AFR's with the open loop tables.

dave w

[ralmo94]

I'm hoping to learn and understand what the tuning expectations and / or ultimate tuning results will be accomplished with resetting the BLM's?

I'm understanding the desired goal to successfully tune open loop only, but I'm thinking it is not necessary to reset BLM's to successfully tune open loop?

Have you tried tuning open loop with the Open Loop AFR vs. Temperature vs. Vacuum table? I tune closed loop, but to I still need to adjust open loop choke AFR's and open loop warm up AFR's with the open loop tables.

dave w

I don't intend on using closed loop. Don't really like the way it plays with the fuel. I Know there are mixed opinions about that. I changed stoichiometric to 14.1 and changed open loop table to mostly 14.1 except the warm up contitions. I left those rich. It seems to be staying open loop now. I tried using blms to dial fuel in when I first started tuning it, and seemed to go a lot quicker once I figured out how to use lambda. It runs way better than it has since I owned it. Just wondered how close people usually get there VE, to call it done.

Thanks.

[dave w]

Open Loop

dave w

[steveo]

...Just wondered how close people usually get there VE, to call it done.

for most cars i like to get it quite close within areas that are actually driven in, and half-ass it or guess in areas that aren't. on most vehicles only like half the VE table is reached within anything but the most extreme cases.

[ralmo94]

for most cars i like to get it quite close within areas that are actually driven in, and half-ass it or guess in areas that aren't. on most vehicles only like half the VE table is reached within anything but the most extreme cases.

Thanks!! I guess I'm pretty well tuned then. That is great news!!! Does a gearhead ever actually stop adjusting fuel mixture? .....

I don't know either.

I want to thank everyone who participated in this thread. Hopefully it will help someone if they have the same issue.

[steveo]

Does a gearhead ever actually stop adjusting fuel mixture?

generally we will play with our engines so much that his target fuel mixture is totally shot to hell on a weekly basis. that's the fun of it.

one mistake is being obsessed with small inaccuracies. don't re-tune for differences in fueling of less than like 2 or maybe even 3%. you will constantly be modulating and NEVER finish tuning. your engine wont notice it at all, so you shouldn't either. only focus on the stuff that's actually out. if you tune with my tools there's usually a filter for percentage, so you can make things under x% just say 'good'...

[ralmo94]

if you tune with my tools there's usually a filter for percentage, so you can make things under x% just say 'good'...[/QUOTE]

I believe trimalizer is yours? I just downloaded that. It was great to be able to leave PE and decel on, and just filter them out with idle. Then filter PE on and see how my PE ratio is.

YOU ARE AWESOME