LSA LTFT reading high at low rpm. What should I do

[hjtrbo]

This looks like the one

 

[07GTS]

ur still neg overlap at .050 so prob easiest is to zero out the "normal RPM" if it isnt already, boundary should be all 520, then the "normal ECT" lower the whole table by 15 so the 110 value should be 95 then see if the idle trims show any richer if so lower it another 5 and should be right there, also make sure desoot mode is disabled

 

[hjtrbo]

Thanks for taking the time. I found the spreadsheet and your name is on that thread. I've got a lot of reading to do now. Those values you mentioned sound familiar from memory. I'll check back in tomorrow. Thanks again for sharing your knowledge!

 

[hjtrbo]

Still reading...

Instead of making a global change, since the problem is limited to low rpm's, can I try and use the RPM table instead like shown? On the spreadsheet it gets me into the white cells for that rpm range and normal operating temp.

 

[07GTS]

are u on the right thread ? that looks to be an old eoit spreadsheet there is a much newer one out now post #389 in this unless u just havnt got to it yet https://forum.hptuners.com/showthread.php?62838-Injection-Timing-Assistance-Requested/page20 what u have done is made it worse as adding to the RPM table advances the injection and u want to delay it, if u set it up as i showed u then u know its in a good spot for idle then after that u can delay it more using the boundary table as rpm increases and keep cells smooth as u transition thru them, higher number in boundary delays injection, dont go too far tho prob 580 in the top end if it likes it best to check with wideband tho as u can see any changes in fueling if its not quite right

 

[hjtrbo]

Argh, yes, sorry.

Still reading. And yeah I was on a different thread that is also many pages long!

Damn, there is some work in that new sheet. Impressed.

I've reached my knowledge point. Time to let some things sink in. This is why I pay my tuner. Spent all day today reading and probably the next couple at least.

Thanks for your help, heaps to learn...

 

[07GTS]

because there is always something going on in the background we cant see i find the way of lowering the ECT table until ur trims show richest and then keep it there best as then u know where that point is even if the math dosnt suit, so i like to delay it only enough to get all u can in the chamber by said tests and that is idle done, then u can add to the above idle cells if it helps cruise and top end just keep it smooth, with yours boundary table id prob put 520 in the 0-512rpm cell and 550 in the 7168rpm cell and above and then inter-populate between cells and then smooth edges, also best to change eoit then go for drive for like 10-15 mins make it all set in then see what idle trims are like after that, just adjusting it and then idling may show false results as there are some startup adders that can change fueling especially after a flash

 

[hjtrbo]

That new sheet is the ducks nuts. I don't have injector pulse width data yet (next week when the weather clears i'll head out somewhere quiet & straight). But playing around with the numbers and watching the graphs change on the last page helps it to start to click in.

 

[hjtrbo]

OK, i'm making progress. The VVE table is still stock but the car makes 497kw at the hubs??? So, I bumped it up globally 15%. Tip in knock is gone now and the charger makes this almighty scream then the ass squats down to the tarmac and off we go. It's never done that before! I usually get a whole bunch of tip in limiting. Not any more!!!! Rock solid 21-22 deg of timing, near flat line of 850Nm showing on the scanner with no torque management or knock retard showing. So much better than before. I need to invest in a wideband and follow the steps to tune the VVE table properly.

I adjusted the fuel injector boundaries as you mentioned. I went with 550 down low then a blend to the factory default of 520 from 2000rpm up. The idle is more robust and I have more idle torque. I mean that I can now roll down my grass driveway not having to touch the pedal where before I could not do that. Idle rpm and airflow has not changed.

Long term fuel trims have come down to 5 to 10% in the original problem area so I am heading in the right direction.

07GTS thanks for you nudge in the right direction!

I still get lean trims when the spark table is in coast down mode. DFCO is on but the scanner shows it is not active. I will try again with DFCO turned off and see what it looks like when running on the coast table.

 

[07GTS]

I adjusted the fuel injector boundaries as you mentioned. I went with 550 down low then a blend to the factory default of 520 from 2000rpm up. The idle is more robust and I have more idle torque. I mean that I can now roll down my grass driveway not having to touch the pedal where before I could not do that. Idle rpm and airflow has not changed

was opposite the 520 at idle then the 550 up top and blend to it as long as u done the ECT normal set the 110 to like 80-90 ? ur prob still ok as is but u dont want to delay too much at idle after the EVC has happened, yes u need a wideband to dial in any power or OL, can be scary when the VVE isnt touched as if the MAF and VVE are too far apart (it always references VVE as a check) and it will default to the VVE as its a calculated fueling situation encase the MAF isnt working properly so if the VVE isnt dialed in and it defaults to it then u could be in trouble, sounds good tho its always the little changes no one really does that make the gains