$OE 7427 lean cruise?

Found information online, and in the definition file so I figured I'd try it out.
I made the changes in the bin, and desired AFR dash display follows the table values.

However WBO2 is still showing the AFR ~14.7 with only momentary swings towards the desired AFR.
BLM numbers are only a couple digits higher as well (vs. without the bin changes).

Not sure what else to try to get it working?

I'm running the 7427 $OE BLHH bin on an AMC 360.
I'm also using the simulated NB output from the WB to NB PCM input if that matters.

VE is tuned pretty good (I think), last log averages looked pretty good to me.
Attachment 3593

Post a log file!

Alrighty

Cool! It's trying to work. So you did this in:
Open Loop AFR vs. Temperature vs. Vacuum

Trying to find an area for lean cruise? Did you set the bit for it?
Tips: Normally used for open loop but can be used in closed loop if L400D Bit 0 "Open Loop AFR Enabled" is enabled and temperature is greater than L48CE "Minimum Temperature for Closed Loop" and temperature is less than L48CF "Maximum Temperature for AFR Lookup in Closed Loop".

What's happening now is the INT is trying to correct and going nuts doing so.

Yes, it tries to work I could tell that right away just from the different behavior of the WB.

Here's what I changed.
Attachment 3602

What else do I need to do to try and get it working as desired?

Upper and Lower Temps for Open Loop Enrichment in the bin I'm looking at are set so it never comes on.

Alos that table your adjusting "Open Loop AFR vs. Temperature vs. Vacuum" is not MAP, it is vacuum kpa, so 0 column is 100 MAP. It's backwards of what we are used to working with.

Also Lean AFR limit is set to 16 your hitting 16.1 so that could be an issue. I have run 16.2 for years with no issue.

Be careful with your wide Band readings! Reset it. Most all WB controllers are Lambda and convert to AFR. If it's set stock to 14.7 for gas and you use E10 it will still read 14.7 to one (Lying) because it only knows Lambda, it's acutaually closer to 14.1, Lambda is 1.0 for gas and 1.0 for E10. Lambda is like Stioich 1.0, it does not matter what fuel, narrow band o2 sesnors adjust to Stoich 1.0 and does not matter what fuel, WB reads it as Lambda 1.0 no matter what fuel.

Set the wideband for lambda and forget AFR. 1.0 is perfect, usual cruise is .98 to 1.00, .85 is rich for PE, 1.15 is lean for lean cruise. Won't change if you change gas.

You sure about that?
Tthe definition states - If engine temperature is LESS than what is set in Maximum Temperature then the table is used.
It was originally set to -0.3C in the bin, I maxed it out.

Good catch on the Vacuum, WTF everything else is MAP sneaky bandages.
I'll change the table.

BLHH Lean AFR limit is 16.5

Far as the WB display I left it alone because my understanding was lambda is lambda and the display is just a conversion.
Since the bin is set for 14.7 I left it alone.

Quote:

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Originally Posted by babywag

You sure about that?.

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Yes, look hard, the 2 you changed are differant then the ones I mentioned.
"Upper and Lower Temps for Open Loop Enrichment"

I thought the PCM stayed in closed loop for this?

http://www.gearhead-efi.com/Fuel-Inj...ull=1#post5735

No reference to these in the above, or the definition file, or a thread I found on another forum.

@ any rate I tried changing what you suggested, and same result desired AFR is not achieved while cruising.

The PCM is trying to use the table, that's pretty obvious to me, but there is something else that's reverting it back to 14.7.

It's commanding it but INT is still correcting. Got to be one of the settings from the link we are missing. Wish I would have worked this out when I had one.

Quote:

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Originally Posted by 93V8S10

There is a way of doing something similar to lean cruise in $E6, $0D, $0E, and $31. $0D listed.

Title: Open Loop AFR Enable
Location: 400D-Bit 0
Usage: Air Fuel Mode Words
Tips: Enables use of L4BB4 "Open Loop AFR vs. Temperature vs. Vacuum" table for closed loop fueling, when coolant temperature less than L48C7 "Maximum Temperature for AFR Lookup in Closed Loop". Can be used for a "lean cruise" or other specific fueling conditions.
I enabled this

Title: Maximum Temperature for AFR Lookup in Closed Loop
Location: 48C7
Usage: Closed Loop Qualifiers
Tips: If temperature less than setting, table at L4BB4 "Open Loop AFR vs. Temperature vs. Vacuum" will be used for closed loop fueling instead of L48DD "Stoichiometric AFR", but only if L400D Bit 0 "Open Loop AFR Enabled" is enabled.
I maxed this out

Title: Stoichiometric AFR
Location: 48DD
Usage: Open Loop AFR Parameters
Tips: Used if temperature greater than L48C6 "Minimum Temperature for Closed Loop". Used if temperature greater than L48C7 "Maximum Temperature for AFR Lookup in Closed Loop" if L400D Bit 0 "Open Loop AFR Enabled" is enabled.
My temp is above minimum temp, and below maxed out maximum temp, Open Loop AFR is enabled so it should NOT be using this.

Title: Quasi- Closed Loop Lower AFR Limit
Location: 48DF
No description so ???

Title: Open Loop AFR vs. Temperature vs. Vacuum
Location: 4BB4
Usage: Open Loop AFR Tables
Tips: Normally used for open loop but can be used in closed loop if L400D Bit 0 "Open Loop AFR Enabled" is enabled and temperature is greater than L48C6 "Minimum Temperature for Closed Loop" and temperature is less than L48C7 "Maximum Temperature for AFR Lookup in Closed Loop".
Again my temps are between values and Open Loop AFR is enabled, and it is using this table.

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Any idea on Quasi-Closed Loop Lower AFR Limit?

Quasi Closed Loop changes O2 fueling by turning off LTFT/BLM...Works with commanded AFR which is normally set to 14.7 (although E10 is lower) I'm really not sure how it works in this mask/OS, but it looks to lower AFR, but you want it to raise? In other operating systems it is used with the same type "Open Loop AFR vs. Temperature vs. Vacuum" table you are using.

So I think your on to something.

Code:

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L48DF  FCB  147  ;14.7:1 AFR, lower limit for quasi-closed loop

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Code:

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L0052 EQU $0052  ;Status word
    ; b7=In quasi-closed loop

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Code:

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;~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; Here for quasi-closed loop
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;
LE2CB BSET    L0052,#$80  ;Status word, set b7, quasi-closed loop enabled
;
 LDAA    L026D  ;AFR
 CMPA    L48DF  ;Lower AFR threshold for quasi-closed loop
 BCC    LE2D9  ;Bra if AFR >=, allow quasi-closed loop
;
;-Disable quasi-closed loop
;
LE2D6 BCLR    L0052,#$80  ;Clear b7, no quasi-closed loop idle if richer
    ;then stoich

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Code:

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;~~~~~~~~~~~~~~~~~~~~~~~~~~~
; Long term fueling is lean
;~~~~~~~~~~~~~~~~~~~~~~~~~~~
;
 CMPA    L4907  ;Max allowed INT
 BEQ    L89AD  ;Bra if INT maxed out
;         
 BRCLR  L0052,#$80,L8995 ;Status word, bra if b7==0, no quasi-closed loop
;
;-Using INT alone for initial corrections, limit INT to removing fuel only
;
 CMPA    #128  ;Neutral INT
 BCC    L89AD  ;Bra if INT >= 128
;
;-Full closed loop here
;

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I just looked @ 3 different $OE bins....
ALL of them have a value of 25.5 for Quasi-Closed Loop Lower AFR Limit

Hmmm