I'm working with the modded AUJP VEx2 bin. I'm using it on a 305 and everything works well so far.

I'm slightly confused on cold start-up. The datalogger shows ~11° SA on start-up. The SA then slowly falls until it gets to zero. At this point it will idle but not very well. Once it gets to 112°F it goes to closed loop and the SA jumps to 18-20° SA.

Does the $8D use the cold comp SA table the same way $42 does? I have a datalog file I converted to a .CSV file. I put it on www.moates.net/fileman under the datalogs section named idle_sa_prob.csv.

If you check the datalog out, look at frame 668. That's when it went to closed loop.

 

I believe I have this exact same issue. It seems as though 12-15 degrees of spark advance is missing? Except I don't think it has anything to do with closed/open loop (I could be wrong).

I took a look at a datalog and the $8d hac carefully today. Your spark advance jumps to normal at 113* coolant temp, just as mine did. At the same frame (I'm using Moates scanner), something called "warm kickdown request" jumps to 1 then back to zero. And something called "warm kickdown enable" switches from 0 to 1 and continues. After that, the spark advance looks as expected. (But, I've also had it where my car was much hotter than 113*, and the spark advance was still retarded.)

I'm definately no code expert, but these 3 sections looked to me like they could apply (maybe more).

;-------------------------------------------
; HOT RESTART RETARD S.A.
;-------------------------------------------
L802F: FCB 113 ; 45 DEG C, IF COOL < DISABLE HOT RETARD, (113F)
L8030: FCB 1 ; 0.4 DEG SA, HOR RESTART RETARD (256/90)
L8031: FCB 113 ; 44.5 Deg C, IF COOL >= Disable cold spk, (113F)
L8031: FCB 255 ; 151 Deg C, if diff cool >= disable cold SA
; ARG = TEMP * (256/192)


**********************
* 400 RPM - 4800 RPM
* MAIN SPK TBL
**********************
BRSET L0001,#$40,LB924 ; Br IF WARM Kickdown enabled
LDAB L005D ; FLT INV COOLANT TEMP
CMPB $8033 ; COOL LOW ENOUGH FOR COLD SPARK ?
BCC LB91D ; Br aROUND LOGIC IF NOT COLD ENOUGH
; ... else
SUBB L0060 : CALC DELTA COOL TEMP SINCE START UP
; TEMP, (DEG C+40) * (256/192
BCS LB920 ; Br If DELTA NOT BIG ENOUGH
; .... else
CMPB $8022 ; TEST POS DELTA
BCS LB920 ; Br IF DELTA NOT BIG ENOUGH
; .... else
LB91D: BSET L003C,#$40 ; WARM KICK Dn REQ
LB920: LDAB #176 ; Max LOAD AXIS ON 1ST WARM PASS
BRA LB946 ;



; HOT RE-START RETARD
;
;---------------------------------------------------
BRSET L0001,#$20,LB9DB ; Br if IAC kick dn enab
; ... else
LDAB L0060 ; START UP COOLANT THRESH
CMPB $802F ; IF COOL LT 45c, DISABLE HOT RE START
BCS LB9DB ; BR IF S/U COOL LT 45c
; .... else
LDAB L001A ; ENG RUN TIME TIME + 1
SUBB $8672 ; IF ENG RUN TIME < 25 SEC ENABLE
; HOT SA RETARD
BCS LB9E1 ; BR IF RT LT
; .... else
LB9DB: CLRB ;
BSET L0001,#$20 ; SET, IAC KICK DN ENABLE FLG
BRA LB9E4 ;
LB9E1: LDAB $8030 ; HOT RE-START SPK RETARD, 0.4 DEG SA
LB9E4: BCLR L003A,#8 ; CLR HOT RESTART RETARD BIT
STAB L0459 ; SAV SKP FOR HU
PSHB ; SAV SKP FOR PGM
BEQ LB9F0
BSET L003A,#$08 ; SET HOT RESTART RETARD ENABLE


Could someone please help explain the significance of "kickdown enabled" and how/if it affects spark advance? I tried searching but couldn't find anything that looked like it was applicable. Any help would be greatly appreciated!

 

I looked through a log from a month ago and saw the same type of thing.
Never noticed before and would also like to know why this is.
Trails off while it is cold then is added back in (all at once?)

Closed loop comes in just after the second "hump" on the left side of this pic.

 

In my latest datalog, the spark advance kicked in about 90 secs after the switch from open to closed loop. The spark advance jumped 14* in one *frame*. This is very frustrating because sometimes the spark doesn't kick in at all, even after warming up. I end up with only 5-10* of advance at idle, and a very rough running car.

I could be wrong, but I don't think that this issue is directly related to closed/open loop operation. I think it has something to do with one or more of these (i'm getting these terms from the comments in the $8D hac):

Hot start retard
Cold engine spark advance
Warm kickdown enable

Unfortunately, I don't really understand what these terms mean.

 

Could you please explain how this works in $42?

 

I'm pretty sure that the cold comp SA table in $42 was active all the time.

In the ASDU cal you had a 20° cold table bias. So the parts of the table that were at operating temp where you didn't want any additional advance you put 20°. That way the ECM would figure 20°(table) - 20°(bias) and it would zero itself out.

There is a similar bias in $8D but this whole disable temp thing has me thrown off. I don't see why you'd need that since the bias is there, which zero's out the table at operating temp.

Right now I have this...
...set to $0 so it's disabled all of the time.

 

For now, I will try the same thing. I didn't realize it, but the "Super8d" ECU that I've been using has this as a constant labeled "Spark Advance Cold Disable Temp."

Thanks!