TLIQ tuning.

[catman3126]

Tuning TLIQ



I have been tweeking the Torque limited injection quantity table at first I increased it too much and it shifted terrible. but in doing so I learned something. Some people with lly's complain that they are sluggish. well when I increased this table across the board lets just say things were not sluggish to say the least.. in fact it was like driving a supercharged fuel injected gas rig......when I first stabbed the throttle it jumped and lit the tires up effortlessly which was great but the shift was bad as it had no defuel at all. I didn't run it like this long at all and backed it down. but damn there's the throttle response most of us are looking for. I haven't had a chance to do much more with it but I will this weekend. just thought I would see if anyone has some imput on tuning this table. I would like some better throttle response and thi sseems to be a limiting table that is standing in the way of that. thanks for any help.

[cmitchell17]

Im pretty sure there is no limiting going on as long as the Max Torque pid is in a range where you are commanding full fuel on the TLIQ. I havent driven a lbz or other duramaxes so its hard for me to compare the throttle response to my LLY, but I feel that LLYs just take forever to spool with a stock turbo, or either i have a boost leak somewhere. Do you have a log to post with commanded mm3 and DMAX torque DMA logged?

[catman3126]

Well I didn't think so either but if you are able try setting the whole table at 105 or so except for the top row of cells and see what you think. I can tell you from my own experience that it woke things up tremendously. Atleast on mine anyway.

[cmitchell17]

I will try that but Im thinking it should just fuel 105 mm3 any time a torque reduction request event happens?

Look at this thread, now that you said that the TLIQ table could just be a constant reference and then the defuel request is further adjusted by the Torque reduction percentage request in the TCM.

http://forum.efilive.com/showthread.php?18382-TLIQ-vs-BT-vs-TLIQ-or-some-such-thing

[catman3126]

I have even shut the torque messages off from the trans, it shifts really firm with it off but doesn't change the responsiveness at all.

[cmitchell17]

The whole defuel strategy is a complete mystery at least to me. Everyone seems to have a different explanation, I always thought the defuel was commanded when requested by the tcm according to the max torque pid referenced from the TLIQ table, but then I never understood how to torque reduction percentage and torque limit tables in the TCM worked with the PCM tables to defuel.

[GMC-2002-Dmax]

TLIQ does exactly that, it limits the amount of fuel when the shift is requested and when you go WOT.

If you raise the TBIQ table mm3 "number" and not the TLIQ table corresponding "number" to compensate you get a bad defuel, if you raise the TLIQ too much you get a nasty flare on the shift.

The key is to change them both and it doesn'y always work the way you intend based on how you alter the Main Injection Pulse tables.

It takes a while to figure it out, but you will eventually get it

[cmitchell17]

Is the TLIQ a base table and then it is further reduced in percentage by the min/max torque reduction request table in the TCM.

[GMC-2002-Dmax]

No, only if you have an 8.1 gasser is that table used, and turning off the defuel request is a good way to wreck your trans quickly.........another tuner liked to do that and tore up a bunch of transmissions by eliminating the request to defuel on the shifts.

[catman3126]

No, only if you have an 8.1 gasser is that table used, and turning off the defuel request is a good way to wreck your trans quickly.........another tuner liked to do that and tore up a bunch of transmissions by eliminating the request to defuel on the shifts.

So Tony where do you adjust the TBIQ and TLIQ tables and am I way off that the TLIQ does seem to give better response? thnaks for the help and glad to have an experienced tuner that will help out.

[GMC-2002-Dmax]

The ecm has many limit tables built into it, MAF limiting, Timing Limiting, Fuel Pressure Limiting..........etc.
Also there are add on tables, that add fuel pressure, timing, fuel, etc all based off ECT, IAT, BARO, etc.

Then you have the TQ limit tables on the 2003/2004 LB7's and the 2004.5/2005 LLY's is table B1106.

All those tables mean something and do something.........the key to learning how they all work is to only change what you have to and make sure it changes and doesn't stay the same, you have to diligently log the changes to learn what they do and they affect the engine and the power/driveability.

If you raise the numbers in the TBIQ table and do not alter the Base Tq and TLIQ tables you won't get it to shift right or respond, but you still have to address the other limiting tables and add-on tables so that it will do what you are asking it to do.

My best advice is to study the way the factory set up the tables and make your changes small and few, then as you see the results when you try to fix whatever you do not like only change one table at a time until you get the desired results or else you could be chasing your tail for a long time

[LB72004]

If you raise the numbers in the TBIQ table and do not alter the Base Tq and TLIQ tables you won't get it to shift right or respond, but you still have to address the other limiting tables and add-on tables so that it will do what you are asking it to do.

My best advice is to study the way the factory set up the tables and make your changes small and few, then as you see the results when you try to fix whatever you do not like only change one table at a time until you get the desired results or else you could be chasing your tail for a long time

true, true, true. been there done that. kept kicking myself in the head until a light bulb went off (don't recommend that last part) . i now have a much better grasp of the TBIQ/BT/TLIQ and their relationship. makes tuning much faster, not to mention safer.

listen to what the experts have to say, then study, study, study then apply. you are better off knowing what you are doing then guessing. if you have to guess then start small and log it until you know what you are doing.