Duramax Diesels Forum Truck of the Week
  #1  
Old 11-19-2017, 10:48 AM
TheBac's Avatar
TheBac TheBac is offline
Why do I keep doing this?


 
Join Date: Apr 2008
Location: Mid Michigan
Posts: 10,800

Default Cold weather tuning changes?

Ive read more threads than I care to where someone is concerned with excess gray/white smoke on cold starts in the winter. I have this same issue along with the engine "chugging" until it gets some heat into it. Its been three years and Im tired of it.

In a recent thread, Dave made mention that some changes could be made, but I have no idea what. I realize my larger injectors (30%-ishs) and lower compression (similar to LBZ) play a role in all of this, but what can I change within my tuning to help somewhat alleviate these ridiculous cold starts??
__________________
Tom
"BBT" 2003 GMC CC/SB 4x4
12.14@111.15

"Flyin' Brick" 1999 Chevy 1500 RC/SB 2wd -- in progress
2014 Chevy Cruze Diesel -- the DD

Two wrongs dont make a right, but three rights do make a left.

Reality is a matter of perspective.

This forum isn't for the weak of heart.....or wallet.

From mufflerguy on yb,
"Lets build a race car they said. Itll be fun they said. I don't know who "they" are.........but they need a good punch in the face!"
Reply With Quote
  #2  
Old 11-19-2017, 11:15 AM
clrussell's Avatar
clrussell clrussell is online now
pro-procrastinator
 
Join Date: Sep 2013
Posts: 4,542
Default

Sure all of your glow plugs are working?

Started mine this am 30 ish degrees no glow plugs and 45%s.. chugs about 5 sec and clears up smoke in about a minute
__________________
01 ext cab, Billet ihi, trans with g converter, sac 45s, tap shift, lots of black, everything built by myself with help from some of the best in the buisness.

Thanks to everyone on this forum who has helped me and those whom I bought parts from.

Special thanks to Evan, James, Russell, Mark and all the others I'm forgetting.
Reply With Quote
  #3  
Old 11-19-2017, 12:11 PM
2004LB7's Avatar
2004LB7 2004LB7 is offline
Hotrodder
 
Join Date: Dec 2010
Location: Norcal
Posts: 689

Default

I've had success with tables {B0915} "Injection Timing ECT (C)" adding 1 or 2 degrees at idle. and {B1002} "Fuel Pressure ECT". I liked fuel pressure at idle to be around 5500 - 6500 PSI seemed to help

{B1004} "Fuel Pressure IAT" & {B0917} "Injection Timing IAT" may also help but I zeroed mine

you can also mess around with the multiplier tables for these ones too for making it use them at what ever temp you like

this was for stock injectors but should help larger ones
__________________
2008 Chevrolet 3500HD DRW LTZ
285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.
Reply With Quote
  #4  
Old 11-19-2017, 02:25 PM
DAVe3283's Avatar
DAVe3283 DAVe3283 is online now
Heavy & Slow



 
Join Date: Sep 2009
Location: Boise, ID, USA
Posts: 2,488

Default

Time to tell my secrets, I guess

As a quick baseline, if you start with my No Logic 3.0 tune, you can look at what I did to the Injection Timing ECT tables ({B0911} through {B0915}). You will notice they are NOTHING like the stock tables. For example, {B0915}:

Stock is on the left, the smooth one on the right is mine. I have no idea what GM was smoking with the stock LB7 tune, it is garbage in the cold.

The real trick here is not the values in this table. We don't actually care. What we want is the final injection timing to be reasonable. I made an Excel spreadsheet to add (some fraction of) the ECT modifier on to the base timing, and show what it will be. Better still, the spreadsheet lets you put in the desired final cold timing and your current hot timing, and it will generate this table for you. I have attached that spreadsheet (Misc Tools.zip), you want the "LB7 Compensator" tab. I make no warranties that the rest of the crap in that spreadsheet is any good, I wrote it randomly for who knows what, so use carefully and please don't judge WTF I was trying to do.

So go ahead, grab my tune, use the spreadsheet, and see what the final timing I was going for is. That is a reasonable start for a stock injector LB7.

But wait, there's more! I attached my current built motor tune, which has SAC 75% injectors and a big stupid cam. Do the same thing with that tune and see what I was going for with timing there. Tom, you probably want your timing somewhere between those two values.

The other big table you need to concern yourself with is {B1002} Fuel Pressure ECT. Do the same trick (with the Excel sheet) to see what final values I am targeting on a stock and built motor.

Oh, and if you see the "Modifier Multiplier" in my spreadsheet, that comes from the "<whatever> Multiplier" table that matches the name of the above tables. You can play with that to adjust how strong the cold engine compensation is for any given coolant temperature. See how I played with that too in my tunes.

Finally, there are a few other tables to look at to get it to start and run nice in the cold. Everyone, please adjust {B0731} Cranking Injection Quantity if you have larger injectors. That fart of black smoke when it lights off isn't cool, this isn't a Cummins, let's get things running right, not fart-y. And the last few are your pilot quantity and timing tables, which have ECT references as well. That usually isn't as big of a deal.

From what I found, the various IAT referenced tables don't work, even if you populate them, sadly. Hopefully this helps!
Attached Images
File Type: png {B0915} stock.png (14.2 KB, 119 views)
File Type: png {B0915} NL3.png (12.9 KB, 116 views)
Attached Files
File Type: zip Misc Tools.zip (274.8 KB, 4 views)
File Type: ctz No Logic 5 BETA r20170515.ctz (327.3 KB, 3 views)
__________________

Reply With Quote
  #5  
Old 11-19-2017, 03:43 PM
Dozerboy's Avatar
Dozerboy Dozerboy is offline
Hotrodder
 
Join Date: Jun 2009
Location: TX of course
Posts: 3,148

Default

Dave did it way better them me. I think Simon posted a timing spreadsheet that had ECT on if years ago. I used it to correct my the ECT from current to get them to what they where trying to go stock. Works great for me down to -5*. I would like to play with them more to get away from the crazy shit GM did, but if I driving in temp below 40* I'm on vacation and don't have time.

Sent from my SAMSUNG-SM-G900A using Tapatalk
__________________

06 GMC 2500 CCSB SLT LBZ 4X4





These views expressed on this post are not my own, but rather randomly generated computer gibberish, and in no way should be used to judge the author's IQ or mental health.
Reply With Quote
  #6  
Old 11-19-2017, 05:21 PM
rcr1978's Avatar
rcr1978 rcr1978 is offline
Hotrodder
 
Join Date: Apr 2007
Location: Spring Creek, NV
Posts: 514
Default

Dave there is some nice spreadsheets in there thanks!
__________________
04 LB7 ECSB down with a cracked piston, build in progress- Wagler narrowed Rods, Callies billet crank, Mahle Race Cast pistons, Randy's Girdle, Wagler/Callies Stage 1 alterfire cam, Exergy 100% SAC's, 2 CP3's, S475/Stock twins.
2010 LMM CCLB-Tuning/Exhaust
2015 LML Cab and chassis- Tuning/Exhaust
Reply With Quote
  #7  
Old 11-19-2017, 07:51 PM
malibu795's Avatar
malibu795 malibu795 is offline
misspeelleerr

 
Join Date: Apr 2007
Location: in the buckeye state
Posts: 7,121
Default

I did similar thing at Dave did but not near as fancy.. end results was same...
Watched the tunes/logs plots log enough I know where I'm at 80% time on a given table
__________________
Adam
mispeeling wrods n a thraed nere u
07.5 3500hd RCLB LMM GT4088R, 4.56 gears 225/70/19.5 efi live 478k broke block
99 FL60 8.3 12v 13sp
Quote:
smooth seas never made a skillfull salior
Reply With Quote
  #8  
Old 11-19-2017, 11:45 PM
THEFERMANATOR's Avatar
THEFERMANATOR THEFERMANATOR is offline
LEGALLY INSANE
 
Join Date: Feb 2009
Location: ZEPHYRHILLS, FL
Posts: 3,465
Default

Also try bumping your idle speed up. I had problems with hazing in the cold when I had my idle set down to 600. Set it back to 680 and it cleared up. Small increases can really add some cylinder heat to clear things up.
__________________
1995 GMC 2500 SUBURBAN powered by 01 DURAMAX/ALLISON, little of this, a little of that,
DIAMONDEYE 4" exhaust, CORSA muffler, AFE stage 1 dry filter, custom tuning by me, KENNEDY single pump and pump rub kit.

Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 08:05 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vB.Sponsors