Update on the 9417 SD 2.0:

I've been working with evo8426 on this. He helped me out big time. I felt so stupid!

So this is what I did:

I took my MAF VE numbers (from my logs) and plugged them into the 3D ROM. The VE numbers were pretty low at idle. Much lower than my 2D RPM numbers.

This is what evo8426 did:

He richened up my 3D VE Map and it idled and revved!!! It's extremely rich, but it revved.

The questions are why does the 9653 2.0 rev with my MAF VE numbers and why didn't I think of what evo8426 did?

I haven't had time to tune it, but I will this weekend. I just wanted to get this on here ASAP, since I was saying the ROM didn't work.

 

OT:

Jamie,

I'm tuning a guys car with MAF VTA and it has the clutch in = idle dropping to 500 or dying syndrome. It seems the ISCV Demand Below 500 RPM Idle Recovery Adder would help this. I assume adding more percentage would help this. Have you done this?

I told him the solution would be recirculate the BOV or go SD. For the meantime it would be nice that his car would have decent clutch in idle.

 

I am logging almost stable steps whaen that is happening, it fluctuates +/-2 steps.

There is "LC1 wb mod" parameter in that log, that is my WB wired in to the ecu.

My idle tables are stock. Except desired idle that is set to 977rpm, and BISS is adjusted accordingly.

I have already read that thread, anyway thanks for the link! I will e-mail you my rom as soon as I get back to my laptop. May be you will take a look and find something that would help.

 

9417 SD 2.0 Update:

I used evo8426 helpful ROM. It wasn't the richening up the 3D map. I ended up with similar numbers as I had when I had trouble.

I went through the rest of the ROM and made minor changes to IPW, ISCV, etc. Flashed and same problem I had before. It wouldn't hardly idle and rev.

I compared the two roms and I noticed evo8426 didn't change my fuel and load limit tables.



I tried enabling one at a time and it had the same symptoms. I disabled them both and it idles and revs. Found it!!!

Now, why didn't he change it? Does it not show up on his ECU Flash XML's? Or did I miss the instructions on not to change it. Or did I just luck out?

 

The load limit doesn't do anything on the SD roms. You set the load limit in the KPA-to-Load Table. If you set the max load to say...200, it won't exceed that value. I don't think I have ever used the fuel limit either.

-Jamie

 

I love reading your posts, Jamie. Wish your shop was nearer.

 

ok I have updated my logs and included iscv items.

 

I've been doing some SD tuning this weekend and found out that GM IAT scaling in SD 2.0 ROM mismatches other ROMs. I haven't checked that thoughtfully before, as I saw "Updated the IAT scaling for the all roms" message in the first post of this thread. But today, switching back and forth from SD to MAF tune I have noticed the difference in logged temperatures clearly.

So I have compared GM IAT scaling in three different ROMS, all downloaded from dedicated threads on this forum - Old good SD, MrFred's patched ROM for MAT logging and SD 2.0. I have used several key points just for comparison:

1) -15*C - freezing winter, substantialy lower than water freezing point - 5*F
2) 0*C - Water Freezing point - 32*F
3) 20*C - "normal condition" temperature - 68*F
4) 50*C - hot underhood - 122*F
5) 80*C - somewhere near normal coolant temperature - 176*F
6) 100*C - Water boiling point - 212*F

Here are voltages, corresponding to that temperatures in different ROMs:

Old good SD:
1) 4.31
2) 3.86
3) 2.94
4) 1.49
5) 0.63
6) 0.37

MrFred's patched ROM for MAT Logging:
1) 4.31
2) 3.86
3) 2.94
4) 1.49
5) 0.65
6) 0.36

SD 2.0:
1) 4
2) 3.51
3) 2.65
4) 1.43
5) 0.71
6) 0.45

You can clearly see that "Old good SD" and "MrFred's patched" ROMs use the same corresponding Voltage-Temperature numbers and match each other ideally.

As for SD 2.0, it uses some kind of shifted values that are close to the true in one area (57*C 136*F), and pretty far from true in another (-15*C 5*F shows as -28*C -18*F).

Assuming that we have freezing -15*C at night and -5*C at daytime over here and it was even colder a couple of weeks ago, and I am trying to tune SD in the worst conditions with large temperature drops (-15*C 5*F as coldest and +45*C 113*F as hottest), that could be crucial and mean that my VE map could be off.


I am thinking if I should correct my GM IAT scaling, or am I missing something?

Any input appreciable.

 

The GM IAT scaling has its own table which ranges from 0-1.1 volts since that is the range of the sensor. I never dealt with any patches for MAT scaling before but I believe the 2.0 SD roms are configured differently from the beginning.

-Jamie

 

I came across a strange issue today when setting up the new tune: injectors are cutting out at random intervals. The IPW is just dropping out completely even though other factors are stable just before.

 

That would be the famous jitter! Now fix it!

 

Yup I've ran into that on 8859 not on 8858 though. It's crappy.

 

Well, the jitter fixes that are listed in the ROM didn't seem to work; I activated each and then all together in various combinations. None seemed to work and with all of them used, this was the result.

Does someone have a quick link to the disassembly and/or op codes? I would like to get into some of this down the road a bit.


EDIT: Oh, and I'm using the 9653

 

Doh...so that's what the SD jitter is, damn .

 

That's no jitter, that's farthing stupid. That would be a major flaw in the programming that would have to be fixed.

My guess is that it's either getting stuck in a loop and bailing or using the wrong set of jump instructions (either missing a transition point in a calc or referencing the wrong cells). I really want to look at the code now.