CALC.VET Struggles, VE Values Don't Seem Sane

[Supercharged111]

I'm wanting to do a CALC.VET to my 97 dually in signature. While I live in CO, I'm on vacation in MI at a much lower elevation and would really like to clean up the VE and MAF while I'm here. My fuel trims are typically pretty good, but PE fueling doesn't deliver what's commanded so I need to start here first. The only mods to the truck are a slightly larger cam, 42# injectors, and a Whipple supercharger. I tried a CALC.VET here last year with my 1500 and the MAF correction values came out sane, but the VE stuff was telling me I needed to double or triple my VE values. I know they're not that far off. I'm using the stickied tutorial:

https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log)

My dually is now telling me to copy/paste with multiply over 3X the present value as well. My OS started life as 12208322, but now is 1270003 so GM.DYNAIRTMP_DMA ought to be defined for it. My Techedge wideband seems to be communicating properly, I put the calc_pids.txt file where I was supposed to, my VE is in g*K/kPa, none of the PIDs have red Xs. . . could this be somehow related to me being 2 bar and not 1 bar? I was able to do this successfully in CO a while ago on my 1500 so not sure what the deal is here today. I've attached a log and the current tune.

23862
23863

Also, here's the calc_pids file I've been using.

23864

I've kept the original as well.

[joecar]

I'll take a look, probably something simple.

[Supercharged111]

Thanks. I'm about to flash in the MAF changes. Simple math tells me I'll be pretty close on PE fueling with just the MAF change.

[Supercharged111]

Joe were you able to have a look? I'm about to set sail back for CO and won't be able to hit all the load cells there I can here.

[joecar]

In the scantool, on the PIDs tab select the pid CALC.CL and then save the file.

On the Data tab check that CALC.VET has a values.

Map should now show values for CALC.VET.

[Supercharged111]

In the scantool, on the PIDs tab select the pid CACL.CL and then save the file.

On the Data tab check that CALC.VET has a values.

Map should now show values for CALC.VET.

Oh it displays those values just fine. Truck runs pretty good so I doubt I need to multiply VE by 3 to get it in check. In fact, in SD, it was showing pig rich above 105 kpa as I'd just plugged in the tutorial values. Plug the MAF in and it's right back down around 11.5:1 that I'm commanding, so I know for sure both are wrong as hell but somehow playing nice together. I won't be back at an altitude where I can replicate this until after Labor Day. I'm lucky it will be so soon though.

[Supercharged111]

I'm in CA now, so can shift some focus back to this. Here's an example from my 1500 that I snagged back in CO. This first shot is after a quick jaunt, the smallest deltas indicate I need to bump around 30-40% while the biggest ones say I need to more than double my VE.

23874

So I did a quick 30% global VE bump, went out for another quick rip, and it's now just as bad if not worse.

23875

I would have expected to see those values get appreciably smaller but they did not. Something isn't right here, I have had it respond properly on other vehicles. That and there's just no way in Hell that my VE table is half of what it needs to be. Since I'm seeing similar values on the dually when I log it, I figure that I'm experiencing the same thing. 1500 has 12212156 based COS5 and the dually has COS3 based on a different OS.

[statesman]

I just had a quick look at the log you posted and your IAT values are insane.

[Supercharged111]

Unintercooled twin screw, yeah they get up there for sure. Trucks still pull harder than they do NA. I often contemplate a turbo with an FMIC, but the blower is there and functioning. The dually in my sig just pulled my ~9000# 24' enclosed car hauler from CO to CA through all those hills, most of which were climbed locked in OD with the AC blasting away in the desert heat.

[joecar]

...Truck runs pretty good so I doubt I need to multiply VE by 3 to get it in check. ...
The CALC.VET map is not the correction multiplier... it is the calculated VE...

The Calc VET procedure corrects the MAF table and calculates the VE table from it.

( you will need to handraulically fill in unhit cells and make other adjustments... eyeball it and use common sense )

On the map, turn on the Data Units.

[joecar]

I just had a quick look at the log you posted and your IAT values are insane.
I had not noticed this, thanks for pointing this out.

[Supercharged111]

The CALC.VET map is not the correction multiplier... it is the calculated VE...

The Calc VET procedure corrects the MAF table and calculates the VE table from it.

( you will need to handraulically fill in unhit cells and make other adjustments... eyeball it and use common sense )

On the map, turn on the Data Units.

Well that would explain why I get the data that I get. I figured it was something stupid like that. Copy/paste with multiply MAF and copy/paste for the VE. Looking back at the tutorial again there it is, I must have glossed right over it and read whatever I wanted to. Thanks!

[Supercharged111]

This last run was a bit odd. For one, I'm seeing the same lame 125kpa here at 2500' elevation that I saw down at 800' elevation, the bypass valve must not be working correctly. Anyway I did get some insane values this time. Some of the cells with low counts and everything above 105kpa is asking for 200 on a table that maxxes out at 10. I'm trying to deal with the rest but man do I suck at blending, I think I went too far with the linear blend tool as there is zero curvature now. Here's the log.

23879

The MAF is doing it too. I wonder if the MAF is being wonky? I just cleaned it a couple of weeks ago.

EDIT: Disregard for the moment, I cracked open the dashboard and the lambda was pegged at 65. I set it to AEM back in CO to snag that log with my 1500 and didn't change it back to the Techedge that lives in the 3500. Good thing I wasted all that time on the VE map!

[Supercharged111]

And it's working just fine now. The more I log the more I realize how many things I still haven't addressed. That said, the truck has been to both sides of the country in the last couple months with a load. It's more the finishing touches as the MAF was corrected less than 10%, in most cases less than 5%, and the VE actually came down in some places while increasing in others. I'm still blown away at how close the stock VE was on this thing, I remember deviating quite a bit farther with the black box on my 1500 way back when.

[joecar]

Post log files, let me look at your MAF signal.

[Supercharged111]

Below is the last calcvet log I took.

23900

[statesman]

Did you switch the tune over to MAF only mode to do that log?

[Supercharged111]

Did you switch the tune over to MAF only mode to do that log?

Doh! I forgot you like MAF only and DFCO disabled. Was there anything else?

[joecar]

+1 what statesman said...

You must run MAF only in order to be able to calculate VE (otherwise you're calculating VE from VE rather than from MAF).

[Supercharged111]

+1 what statesman said...

You must run MAF only in order to be able to calculate VE (otherwise you're calculating VE from VE rather than from MAF).

Man I'm batting 1000. I should have also consulted this thread.

https://forum.efilive.com/showthread.php?16280-CALC-VET-Summary-Notes

I'll check back in after my next logging session.

[Supercharged111]

+1 what statesman said...

You must run MAF only in order to be able to calculate VE (otherwise you're calculating VE from VE rather than from MAF).

Man I'm batting 1000. I should have also consulted this thread.

https://forum.efilive.com/showthread.php?16280-CALC-VET-Summary-Notes

I'm glad you guys caught that. I'll check back in after my next logging session.

[Supercharged111]

I can't make this up. Earlier today I set B0120 to 400 (or so I thought) and B3313 to 140 (successfully) and proceeded to waste my time with a good 20 minute log. Looking over the tune now, B0120 is magically still at 4000. :wallbash:

[statesman]

Doh! I forgot you like MAF only and DFCO disabled.

It has to be in MAF only mode for CalcVET... but I think you now understand why.

Yeah, I like DFCO disabled for tuning... it's a lot easier to work on fueling when the fueling is working.



Was there anything else?

Yep, here's my Christmas wish list for your next log...

MAF Frequency
MAF airflow
TP
RPM
MAP
ECT
IAT
GM Volts
Short term fuel trims
Long term fuel trims
Front O2 sensors
Knock Retard
Wideband (make sure it's calibrated)

You can log whatever other shit you want (I don't care about channel count), but make sure that everything in my list is being logged.

Try to get a good mix of driving in the log. I don't care about WOT pulls yet... I just want to see how bad the fueling is and I can see that from normal driving. Get me at least 12,000 frames on a fully warm engine.

Post your log and also post the actual tune file used to make that log.

[Supercharged111]

Alright I'm sold. Using VE to calculate VE is a bad idea. MAF is about +/- 3% according to the SELBEN (PE fueling was only a couple tenths lean). I know you said no WOT, but, I got some anyway. :hihi: MAF only the truck is less quirky, so that's encouraging as I have not touched the transient fueling on this truck. This is not the truck you've helped me with before, so it should look different. I haven't touched the tune yet, so what's below is what's still on the truck and likely what I'll drive to class in tomorrow seeing how it's actually better this way.


23941

23942

I see advance dropping when I think it shouldn't. It just randomly drops from 38 to 13 with steady throttle. Speaking of steady throttle, when it comes time for the read deal I think I'm going to hook up the trailer. I can't hold it for but a couple of seconds before it goes from 50 to speeding ticket in OD and even the damn bumps in the roads here get my foot kicking back and forth a bit. Truck is stiff as a. . . nahh my mind went right in the gutter on that one. I rarely drive this empty and I never DD it so this is an adjustment. I just hope I got what you were after and there isn't anything weird going on like with my other truck. After this one is right I suspect I'm going to go back to stock VE and stock transients on the 1500 to just start with a clean slate. I'm beginning to wonder if I calculated VE with VE on that one back in 2017. . .

[statesman]

MAF only the truck is less quirky, so that's encouraging as I have not touched the transient fueling on this truck. This is not the truck you've helped me with before, so it should look different. I haven't touched the tune yet, so what's below is what's still on the truck and likely what I'll drive to class in tomorrow seeing how it's actually better this way.

I run my own vehicle permanently in MAF only mode. I just have my VE table close in case I ever have a MAF failure, but I don't spend too much time adjusting it.

The MAF is a sensor that measures the actual airflow... you can't get better than that. Learn to love the MAF.



I just hope I got what you were after and there isn't anything weird going on like with my other truck.

Yeah you got what I asked for... but I'm getting old and I forgot a couple of things, so on your next log I'd like you to also log VSS and Commanded AFR.

Your fueling doesn't look too bad, but what does look bad is your voltage.... it's too low. You've got 12.5v dropping down to 12.0 at WOT. You need to fix that. I recently blew my alternator because my main wire from the alternator to the battery had corroded and since my tune was good I haven't bothered to log my car in a few years, so I didn't know my voltage was dropping.

Get your voltage fixed and then make a new log and remember to include those things I forgot to ask for before.

[Supercharged111]

I've always loved the MAF, and I think it's because it covers up my mistakes in VE. :hihi: I just put a multimeter on the battery at an idle and I'm getting 13.8. At the tail end of my log I was idling at 12.5-12.7, hopefully it's something simple. I think I'll check grounds first and bump EFILive against my meter real time as well. MAF only never really occurred to me as being a viable thing, but now it sure is tempting now. But I also want to get better at fixing VE, and I think I found something that will help: tweaking VE 2D. I saw the picture of it in Shawn's post and it looks easier for me to digest when I'm forced to handraulically change stuff as Joe put it. I can usually nail a couple RPM points top to bottom with 50+ cells and sometimes even the 1 load point as well. With the trailer I expect my odds here will be really good. I think I'll sneak in 3% at the very top of the MAF before I go out again too. That should have me about spot on for PE AFRs. I'm thrilled with how the truck acts MAF only.

[Supercharged111]

Well something is up, I just observed 14.5V at the battery and 13.2 on EFILive, so as far as I can see 2 things are happening: 1 there's a significant voltage discrepancy between the PCM and the battery and 2 there's potentially some sort of heat related degradation. I say potentially because I'm used to seeing mid-high 13s on my 1500 when checked at the battery. Priority #1 is to ID the discrepancy in EFILive vs battery voltage. C'mon, just be an easy ground.

[Supercharged111]

So I've been away from the truck a couple of weeks travelling from coast to coast essentially. On the way I swung by my 1500 which used to suck on startup after the initial fire. I disabled VE on it and lo and behold 99% of the quirks are gone! So apparently I've been correcting VE with VE for some time now. I'm headed back to the dually now and will address the voltage issue upon my return so I can press forward with further cleaning up the tune.

[joecar]

The ECM has it's own voltage measurement circuit which mat/will differ in accuracy/quality compared to a proper voltmeter/dmm.

But, having said that, do check your connections, check for voltage drops in case you have bad connections/wires.

[Supercharged111]

The ECM has it's own voltage measurement circuit which mat/will differ in accuracy/quality compared to a proper voltmeter/dmm.

But, having said that, do check your connections, check for voltage drops in case you have bad connections/wires.

What have you observed in terms of voltage differences between a DMM and what the PCM tells you? I intend to add a substantial ground strap that I suspect does not exist between the engine and frame, then double check my Lextech pinouts for power/ground sources to put eyes/DMM on to verify their condition. I'm basically looking for a limit to sanity checking my due diligence on the powers and grounds for the PCM as it seems the alternator is doing its job based on my voltage readings with engine running at the battery.

[Supercharged111]

I just did a review of my 411 install because I was missing a constant power wire, or so I think. I emailed Lextech to get clarification on that one as his document doesn't instruct you to add a 2nd constant power wire when 411 swapping a 97, but 98-00 actually have this wire in the harness and use it with the 411. At any rate, here's what I observed with the DMM:

Battery: 12.21V
C1-20: 12.21V (constant)
C1-19: 11.48V (switched)
C1:75: 11.68V (switched)

So at this point I need to figure out how this truck is wired so I can narrow down where the voltage drop is. My gut says go right to the ignition switch, we'll see. At the end of the day I'm looking for a component that gets 12.21V in and spits out considerably less. Good call on logging voltage statesman! I'll have to add that to my list of stuff to watch.

[joecar]

I have seen PCM is always 0.5 to 1.0 volts lower than DMM.

[Supercharged111]

I have seen PCM is always 0.5 to 1.0 volts lower than DMM.

I didn't even check the PCM with EFILive as I figured I had a smoking gun with that .5-.7V delta on the DMM switched vs constant. My concern with the discrepancy observed between switched and constant is that switched is what powers the injectors. Crap, I should have compared switched PCM vs the injectors now that I'm typing this. I know the injectors respond differently based on voltage, is that the concern here? Because the charging system itself was good to go way back when I initially checked it.

[statesman]

I know the injectors respond differently based on voltage, is that the concern here?

You can tune out a voltage discrepancy as long as it's a constant discrepancy... my main concern is that your charging system is not working properly.


Because the charging system itself was good to go way back when I initially checked it.

If you're confident that the charging system is good, then don't worry about the voltage discrepancy. Personally, I'd be checking for resistance in the main power wire between the alternator and the battery. Even if you're happy with the ECM registering a lower voltage than your DMM... you should be concerned that your ECM voltage reading is showing your voltage dropping during WOT conditions.

[joecar]

Check voltage drop between alternator and battery pos as statesman said, and also check voltage drop between battery neg and ground (at alternator body).

If you have access to an oscilloscope, look for ripple in alternator/battery voltage.

[Supercharged111]

Yeah, I didn't check anything under load. I was fixated on the wrong thing.