VE tuning issues

[RicksPerf]

Here is what has happened. gen 3 ecm and all related sensors install on a 5.7 Mopar Hemi..(called Hemitronix conversion)
Car was running very well with LTFTS adding +25% fuel. Good power,idle,throttle response. Has been on the road all summer
Decided to tune VE to get ltfts in line.
Failed MAF and other fuel adders, added 15% to VE Primary ,Reset Ltfts . Engine ran very lean ,hard to keep running
Added another 20% to VE and still lean.. Added 40% still lean. rechecked fuel pressure Just over 58psi. no intake leaks or exhaust leaks
Have my LM1 hooked up. narrow band o2s disabled for tuning purposes. Attaching tune file and log files, I tried to upload the 40% log
but it would not upload. still ran lean .didn't make much or any difference. Was hoping some one could check these out before I put the old tune back in and enable the narrow band o2s etc. Still new to HPtuners so I apologize if it takes me a bit to figure things out

[Ben Charles]

Didn’t look at tune... but I would suggest if you are making 40% fuel corrections and no change then I would think it’s still in MAF mode

[RicksPerf]

I have the mass airflow sensor frequency set to zero to fail it. did I miss something?

[curiousg7]

There is a couple steps. You might just need to set the DTCs

https://www.hptuners.com/help/vcm_ed...to_user_sd.htm

[RicksPerf]

did that also (mil on first error) p0101,02,03

[5FDP]

Your computer does not use the Primary VE while in speed density. It only uses the secondary VE, that is how the early GM computers are designed to run.

So that is the reason why nothing is changing. You must apply the changes to the secondary VE table, smooth it and then copy/paste the rows over into the primary VE table and smooth that table. That way in the end they should be super close and it will go back to using the MAF with primary VE table in mixed mode.

You can apply the speed density OS upgrade to remove the secondary VE table if you wish. Makes things must easier. That would require you to flash back to stock, then flash the speed density OS in instead of the MAF enhanced OS. The MAF still functions like stock in a speed density OS.

[RicksPerf]

loaded the original tune and went to the OS tab ,could not access SD OS could it be locked by the previous tuner ?

[5FDP]

Pervious tuner must have sent you the file that was already upgraded to the 1 bar MAF enhanced. The OEM file would have like 2-3 options for upgrade paths.

Being that the truck has a swap harness/computer from a vendor it makes sense that it was shipped that way.

It's not the end of the world, calibrate the secondary VE I said above and you will be just fine. It's just more steps but the outcome is the same.

[RicksPerf]

just to be clear , The primary and secondary tables are already identical. if i make my changes to the secondary table then paste them to the primary table I still keep tuning in SD mode with MAF failed. Then after i am happy with that I go back to Enhanced MAF mode with o2s andLTFTs enabled etc ?

[RicksPerf]

sorry i was typing as you sent a reply looks like you answered my question Thanks for all your help

[5FDP]

In the stock tune they should be identical, just in the tunes you tried to add fuel too is where only the primary VE was changed and that being the problem.

The secondary VE has less resolution so a full copy/paste won't work because it skips all the numbers with 5 in it, like 15/25/35/45 etc etc.

But I think we have everything covered for what needs to be done.

[RicksPerf]

Yes coming into line now. Had to add in the 43% range from the original tune file. AFR bouncing around 14.5 now .I am wondering how the supplier was that far out on his base map. Although the numerical values in the VE maps seem quite a bit higher than most other maps I have looked at. Idle area numbers in the 50's
and high RPM full load numbers over 100. Could I be looking at incorrect injector flow rate numbers or something else?

[5FDP]

Likely something is wrong with the injector data. Be it the flow rate, min injector pulse/short pulse adder, offset data.

[RicksPerf]

Well looks like I may need some help to sort that out. I'll do some research and see where that goes. I should probably start with injector specs if I can
find any thing I guess.

[ChopperDoc]

Injector data is what the PCM uses to decide what the numbers will be on the MAF and VE, but more importantly what the g/cyl number is. What this means is that changing the data will alter your spark map as well. Lets say for example the stock tune uses 30# injectors, but you actually have data for 60# in there, all the numbers on the VE and MAF will end up being doubled on the VE and MAF tables after you tune everything. This also means that instead of the PCM airmass calc saying that there is .50 g/cyl, it will now result in 1.00 g/cly. So this moves your spark map down to the bottom row essentially.

It makes sense though, since if I tell the PCM the volume of a cylinder is "x" at a certain point on the VE or MAF table, but then also tell it that it will spray at a pressure of 60# at "x" MAP value, this will affect the calculation throughout the tune. The PCM has to know how much fuel it sprays per pulse to meet commanded, so it all starts with injector values.

As for the VE and MAF, this is fine and these numbers can be brought in line and changed to match the new data. What you cannot change is the end result, which is what is used for your spark tables, aka g/cyl. The only way to change this is to alter the injector data, typically down in this case, to gain resolution on the spark maps instead of just using the bottom row as the WOT spark area.

The MAF does have a hard coded limit on gen III though, which is 512 g/s. So if it's hitting this, you have to reduce your injector flow rate anyway in order to use the MAF model. This is called scaling.

[ChopperDoc]

Stock numbers are just under 100 on WOT VE, so the fact that you are going over is expected with a modified engine. Well, that's kind of the point of mods, to increase the airflow numbers which translates to power. The injector data used in your tune looks extremely close to the stock values for flow rate, but has been modified. I normally do this too for injectors, as in simply change the slope and not doubling the value or something, trying to keep it near the stock numbers so my airmass calculations stay in a usable range on all my tables, particularly spark.

The minimum pulse and short pulse are in fact still stock numbers on your data. I'd try and get the data for your injectors, since I have no idea what they really are and there's no way to tell just by looking at them. I don't recommend changing the flow rate, since it is in line with stock, so your VE and MAF values should remain in a logical range. If you end up having issue with rich spikes on decel, this is caused by too high of a min pulse or short pulse adder. Both of these are stock in your tune.

Anyway, you're going in the right direction here. And it's okay to have numbers a bit higher than 100 on the VE. I know, lol, waiting for the physics purists to come in and attack me now. But yeah, over 100 is no big deal so long as your spark maps look good, and MAF is under the 512 limit.

The only way to truly bring it under 100 (for the purists to not grumble here) is to reduce the flow rate values on your injectors. What size are they anyway?

[RicksPerf]

Just trying to absorb what your telling me. LOL As far as injector flow rates i am finding that stock 5.7 Hemi injectors flow somewhere between 24 and 27 lbs/hr
at 43.5 psi. Dodge ram 5.7 fuel pressure spec for 2004 and up is 58 psi+- . 31 lb/hr injectors( Which I think are the numbers in the tune) at 58 psi should support up to 450-500 HP.
I dont think the stock 5.7 injectors would be that big. am I making sense?

[RicksPerf]

Dropped the injector flow rate down to around 28 lb/hr . That brought the ve numbers into realistic figures. Re abled the MAF and added some fuel to the MAf freq. Tuned that with LTFTS disabled
re enabled LTFTS . Got the fuel trims right where the should be . Just wanted to Thank you guys for all your help