Spark advance for coolant temp ?

Subscribe
Jul 23, 2003 | 06:40 AM
  #1  
A few days ago I wanted to start working on
PE % change to AFR VS coolant temp and the
Injector PW correction vs Battery Voltage Tables.

7730 8D AUJP

I noticed and can reproduce this this problem that follows.

any time my coolant temp is at or above 100deg "C"
there must be a differant spark advance table involved in the final
spark advance calculation, because I get 10deg more advance above whats in my spark tables.

My PE spark advance is zeroed out.

anybody have any thoughts or idea's on this one.

I'll post some pic's of my data logs soon if I can get my scanner to work.
Reply 0
Jul 23, 2003 | 07:07 AM
  #2  
There are several timing corrections.

One being based on coolant temp., at lower lower temps, there is some timing added.
There is also spark added at startup and then is decayed out vs time.

Are you sure your not just seeing the ref angle?.
Reply 0
Jul 23, 2003 | 07:20 AM
  #3  
Here's some of my data logs.
I'm useing TunerCar 8d ver. AL and I don't belive I see a spark table vs Coolant temp.

Reply 0
Jul 23, 2003 | 04:29 PM
  #4  
This seems to only happen at coolant temps above 100deg "C"
and when this happens I get a lot of spark knock.

When the coolant temp drops to 98deg and below the timing
drops back to whats set in my spark advance tables.

Data logs in post above:
Notice on the first data log at 5350rpm 91deg, a spark advance of 23deg.

Next on the second data log at 5350rpm 105deg, a spark advance of 32 deg. (Way to much)
Reply 0
Jul 23, 2003 | 05:47 PM
  #5  
Quote:
Originally posted by LBSZ28BLOWN
This seems to only happen at coolant temps above 100deg "C"
and when this happens I get a lot of spark knock.

When the coolant temp drops to 98deg and below the timing
drops back to whats set in my spark advance tables.

Data logs in post above:
Notice on the first data log at 5350rpm 91deg, a spark advance of 23deg.

Next on the second data log at 5350rpm 105deg, a spark advance of 32 deg. (Way to much)
As Grumpy mentioned, SA vs coolant is a good place to start.

RBob.
Reply 0
Jul 23, 2003 | 06:59 PM
  #6  
RBob,

SA vs coolant is a good place to start.
where is this table, I don't see it in TC.

I do see a (startup SA vs Coolant) but it only has 3.9deg in it at that temp.

I also see a (Base cool. adv. correction vs load vs coolant temp)
but it has 0.0 in it at that temp.
Reply 0
Jul 23, 2003 | 08:31 PM
  #7  
Quote:
Originally posted by LBSZ28BLOWN
RBob,

SA vs coolant is a good place to start.
where is this table, I don't see it in TC.

I do see a (startup SA vs Coolant) but it only has 3.9deg in it at that temp.

I also see a (Base cool. adv. correction vs load vs coolant temp)
but it has 0.0 in it at that temp.
As far as I know there are no other tables/parameters that will change the SA according to engine temperature, coolant or MAT. Here is the location of the coolant vs SA table:

Code:
;=======================================
;
; COOL SA TBL, 12 BLKS
; $8138 - $81A7
;
; TBL = (VAL + L8137) * (256/90)
;=======================================
I am not familar enough w/Tunercat to know the what the table names are. Also check the lower temp to see if SA is being removed.

RBob.
Reply 0
Jul 24, 2003 | 08:34 AM
  #8  
Here's the responce I received from TunerCat aboght this SA table.
(TC can you add this to the 8d tdf for me.
Here is the location of the coolant vs SA table:
Code:-----------------------------------------------------------------------
;=======================================
;
; COOL SA TBL, 12 BLKS
; $8138 - $81A7
;
; TBL = (VAL + L8137) * (256/90))



Hi Louis,

The current $8D ECM Definition File does contain this table. Its labeled as
"Base Cool. Adv. Correction Vs. Load Vs. Cool. Temp".


Best Regards,

TC


So it apears that this table is the correct one.

the only problem is that there is no SA added for this temp.
I guess I can put in a neg SA of -10 at 104deg "C" and this may solve the problem.

But where is this additional 10deg of SA coming from if its not in the Main spark table and its not in the "Base Cool. Adv. Correction Vs. Load Vs. Cool. Temp" table.

Interesting

Thanks
Reply 0
Jul 24, 2003 | 09:20 AM
  #9  
Quote:
Originally posted by LBSZ28BLOWN
But where is this additional 10deg of SA coming from if its not in the Main spark table and its not in the "Base Cool. Adv. Correction Vs. Load Vs. Cool. Temp" table.

Interesting

Thanks
I think I just may have figured it out. The $8D mask has a forced knock test (I didn't know this!). It may very well be this test being invoked. Here are the DTC43 test parameters from AXCN:
Code:
;------------------------------
; ERROR 43, KNOCK
;------------------------------

L8298:  FCB     100     ; 10 SEC TIME REQUIRED
L8299:  FCB     181     ; 3.62V UPPER VOTLAGE THRESH
L829A:  FCB     72      ; 1.44V LOWER VOTLAGE THRESH
L829B:  FCB     1       ; Add 0.3 deg SA for test
L829C:  FCB     180     ; 95c, Min cool for for ERR 43B
L829D:  FCB     75      ; If MAP < 75 THEN DISABLE ERR 43B
L829E:  FCB     71      ; 24.9 Deg MAX S.A. for ERR 43B TST
Needs to be above 95c and will add up to 24.9 deg SA to force knock. Hmmm. . .

RBob.
Reply 0
Jul 24, 2003 | 12:12 PM
  #10  
I think I just may have figured it out. The $8D mask has a forced knock test (I didn't know this!). It may very well be this test being invoked. Here are the DTC43 test parameters from AXCN:

code:--------------------------------------------------------------------------------
;------------------------------
; ERROR 43, KNOCK
;------------------------------

L8298: FCB 100 ; 10 SEC TIME REQUIRED
L8299: FCB 181 ; 3.62V UPPER VOTLAGE THRESH
L829A: FCB 72 ; 1.44V LOWER VOTLAGE THRESH
L829B: FCB 1 ; Add 0.3 deg SA for test
L829C: FCB 180 ; 95c, Min cool for for ERR 43B
L829D: FCB 75 ; If MAP < 75 THEN DISABLE ERR 43B
L829E: FCB 71 ; 24.9 Deg MAX S.A. for ERR 43B TST
--------------------------------------------------------------------------------


Needs to be above 95c and will add up to 24.9 deg SA to force knock. Hmmm. . .


VERY INTERESTING this makes sense now.

So what do you think I should change:
Maybe the (Min cool for ERR 43B) from 95c to 120c or something,
if so what do I need to change.
L829C: FCB 180
Change the 180 to ?

or can I disable this test and how.

Thanks
Reply 0
Jul 24, 2003 | 12:36 PM
  #11  
Ok I did some research.

L829C: FCB 180 = 95C


X*191/255-40
X=180 *191/255-40 = 94.82C

So if I change 180 to 240
X=240*191/255-40 = 139.76c

this should dissable this spark adder since I'll never see 140c (284F)
Reply 0
Jul 24, 2003 | 01:25 PM
  #12  
OK whats the raw hex address for (L829C) or how do I calculate
from (L829C) to hex.
I'm using PPII to edit the .bin file.

Also I noticed in the Constants a switch labled:
Knock Diagnostic [Error 43] its checked.

if I uncheck it will this dissable this routine thats adding SA when
the coolant is above 95c, that shure would be simple it thats so.

Thanks
Reply 0
Jul 24, 2003 | 01:38 PM
  #13  
Quote:
Originally posted by LBSZ28BLOWN
OK whats the raw hex address for (L829C) or how do I calculate
from (L829C) to hex.
I'm using PPII to edit the .bin file.

Also I noticed in the Constants a switch labled:
Knock Diagnostic [Error 43] its checked.

if I uncheck it will this dissable this routine thats adding SA when
the coolant is above 95c, that shure would be simple it thats so.

Thanks
Unchecking the Knock Diagnostic box will disable all knock testing. This includes the resistance check of the knock sensor/circuit.

With a hex editor just drop the 8000 off of the address. L829C will be address 29C in the editor. Can use the Windose calculator to convert from hex to decimal & back. I would just set the min coolant temperature to $FE, one less then the max.

As a double check for the proper bin location 180 is $B4.

RBob.
Reply 0
Jul 25, 2003 | 08:02 AM
  #14  
OK,
I made the change to my .bin as you sugested (set the min coolant temperature to $FE, one less then the max.)

Hopefully today I'll get some data logs at the high temps,
I have to idle with the A/C on to get it up to 100deg "C"

I'll post my results on this thread.

RBob, Thanks for all the help
Reply 0
Jul 25, 2003 | 01:40 PM
  #15  
:lala: :lala: :lala:

:hail: :hail: RBob

Thats it, the SA stays where its set in the main spark tables.
awsome no spark knock at all.

Also I noticed something else going on but I thinks its a plus, the SA at WOT at 100deg "C" and above is some how pulling one or two deg out of the SA but thats allright as far as I'm concerned.

Now you can tune the SA at all coolant temps with this test out of the calibration.

Many Thanks
Reply 0
Jul 25, 2003 | 03:58 PM
  #16  
WARNING!!!! A noob question coming here:

Since the ECM is adding nearly 10 degrees of timing, that means there is that much room to advance it, so adding some advance, "MAY" be something to consider?

From what I've read, more advance is not always better, but like I said, I'm getting into this stuff soon, and the more of these posts I read, the better prepared I'll be.
Reply 0
Jul 26, 2003 | 01:19 AM
  #17  
JP84Z430HP.
a stock N/A car might.
I'm running Boost (Forced Induction) and more timing at high temps is out of the question.
Reply 0
Jul 26, 2003 | 08:02 AM
  #18  
Quote:
Originally posted by LBSZ28BLOWN
Thats it, the SA stays where its set in the main spark tables.
awsome no spark knock at all.

Also I noticed something else going on but I thinks its a plus, the SA at WOT at 100deg "C" and above is some how pulling one or two deg out of the SA but thats allright as far as I'm concerned.

Now you can tune the SA at all coolant temps with this test out of the calibration.

Many Thanks
Your welcome. I too do not like these types of tests. At least the $8D test creeps the SA in until knock is detected, the $42 & $61 ('747 & '8746) bring it all in at once. First time it happended to me the engine knocked like crazy. Scared me that's for sure.

The lowering of timing when over 100c is from the table "Base Cool. Adv. Correction Vs. Load Vs. Cool. Temp". The catch there is that the table is based on manifold vacuum (BARO - MAP). So at 0 KPa (vac) you are at maximum manifold pressure.

RBob.
Reply 0
Subscribe