VE tuning with HPT Wideband and Narrowband how to

[JimMueller]

Oh, and this was a HUGE help. Also, I have an excel fil I made that takes your hand jammed AFR histogram numbers, your original VE table and creates a new VE table based on Matt's calculations. I even included a 4th sheet that allows you to view the total changes from the original to the new VE table just in case you fat fingered a number wrong. Email me if you want it.

JimK: That sounds familiar... Can you send me a copy?

Matt: I've seen some issues in MAP 15/20 on decel where the AFR reads really lean (15-19). To get it to 13.0, I needed to add a bunch of fuel. I haven't taken it back out yet, but it seems like I'm getting a large amount of backfires now.

[JimMueller]

Can we add something in the checklist to disable DFCO to prevent false lean values during the SD tuning?

I'm curious about the extra changes needed if you put the MAF back on as well. In the 'old days', people tweaked the MAF table to alter the fuel trims, then they changed it to the IFR table, then everything said do it in VE and leave both those tables alone if they were correctly calibrated for their sensors. Aren't we going in circles? Why make changes to the MAF vs. IFR this time around?

[corpsvette]

Besides what Jim M. has brought up about the DFCO, if I decide to stay MAFLESS and go with SD, will I always have to tolerate the 0102 and 0068 code or can I eventually disable them once I have reset my tables EXCEPT THE NEW VE back to stock or do these codes always need to be active to make the SD tune work correctly. I know it was mentioned in the write up not to disable them as they would have adverse affects, I am just wondering if once things are done with the tune if we can disable them. My reason is because code 0068 is causing a SERVICE ENGINE SOON on the DIC when the car is first started despite me setting NO MIL LIGHT in the engine diagnostics. I can make it disappear with the Reset button on the car's DIC controls. Now to decide if I want to reconnect the MAF because I did this morning and my LTFT are extremely high as Jim M. mentioned in another post. My only contributing factor is it was 10 degrees cooler this morning. I will try again this afternoon when it warms up and see if it makes a difference. Thanks guys,

Jim K.

[SideStep]

Can we add something in the checklist to disable DFCO to prevent false lean values during the SD tuning??

SUPER good question...

[Chris@HPTuners]

you can just set any of the entry values to high/low values. eg. MAP entry to 0.

Another thing that you guys will probably come up against is, what do i do if i got my VE and everything right but my LTFT's go +ve when i re-enable closed loop? The answer is either you didn't really get it right, your wideband is a dud *or* you need to take a look at your O2 rich/lean switch points.

Chris...

[JimMueller]

- 'Getting it right' is using the 'Last Afr' values in the histogram between 12.8 and 13.2, no? Or is that not close enough?

- How does one tweak the O2 rich/lean switch points and how do we determine the values?

[WS6snake-eater]

Hey everybody, Sorry I have been working a lot lately. I will be making a few changes today to include the DFCO disable, and also setting up the LTFT boundries, and o2 switch points. Bare with me I should have it up by the end of the night. Thanks for everyones suggestions, I will make the changes throughout the day, and I will try and get everything posted up for you guys, then get back to answering individual questions.

Matt

One other thing I, have seen a lot of questions about people plugging the MAF back in and it throwing off the LTFT's. Yes this will happen. You will need to scale the MAF in order to get your trims back in line, but it is a very tideous process, that deserves its own wirteup. I haven't had a chance to play with it much as of yet, but as long as the weather is ok this weekend, I will try to get the process nailed down, and written up for guys. I have seen a spreadsheet out that helps to get the MAF dialed in, but it didn't quite work the way I expected it to. So I will be playing with that some as well. Patience grasshopper.

[corpsvette]

I gotta agree with Jim M. on this one. I am scratching my head. I pretty much had 13.0 nailed across a majority of the cells for 2 different 20 minute logs. So either my MAF is really jacked or my LM-1 needs a new sensor already. Matt you are out doing yourself but I for one greatly appreciate it. You have expanded my programming experience 4-fold. Keep up the awesome work but don't forget to take some time for yourself man. We'll still be lurking about when you figure it out so you can teach the inexperienced. I will keep playing with it. THanks to all again.
What if we raise the AFR to 13.4 or something a little higher. Do you think your goal of 13.0 might be a little rich? Just wondering, I don't know or understand why 13 is the base line so I just gotta go with your experience ;D. Lastly, will changing the DFCO, say MAP to 0 as mentioned by Chris hurt anything over the long run?

*Edit Ummm, I need better directions on what and where to change the MAP to 0. I went to Edit->Engine->Fuel Control->Fuel CUtoff/DFCO...now what? The one MAP I see is under clutch and is already 0. THanks. *end of edit

Jim K.

[Dirk_Diggler]

13.0 is the baseline because it isnt too rich and isnt to lean for you to hit all the points on the ve table. 13.0 is just an arbitrary SAFE NUMBER used so no one cooks anything....

Does DFCO really affect your averages? From my experience DFCO puts the car in open loop so the trims stop learning and you should get a whole bunch of 0's assuming you are doing this in closed loop as opposed to doing this in Open loop using a WB

In the histogram I would use the averages as opposed to the last value. Averaging is a better, more resolution picture of the cars fueling requirements over a period of time. Using the last value only gives you exactly that. That one and only frame befroe you stopped logging

[Dirk_Diggler]

2 Questions
1> Will this approach work with a supercharged truck. I assume yes since under part throttle/non boosted MAF calculations are same.
2> LTFT's are much different on the on the 2 banks of my engine based upon logs I have done. The histogram combines these values apparently and expresses the percent in one value. By tuning via this method do I risk running one bank lean yet still look good via the histogram? Do I need to figure out the unbalanced fueling first?

Completely new to this. TIA for any input.

No it wont work in a SC'd truck. Your map sensor doesnt read boost and will max out as soon as you go over 14.7 psi or over 1 bar. If your Trims are different between the banks you may have a dead or extremely sleepy o2 sensor that may need to be changed

[WS6snake-eater]

No it wont work in a SC'd truck. Your map sensor doesnt read boost and will max out as soon as you go over 14.7 psi or over 1 bar. If your Trims are different between the banks you may have a dead or extremely sleepy o2 sensor that may need to be changed

Or an exhaust leak!

[KySilverado]

No it wont work in a SC'd truck. Your map sensor doesnt read boost and will max out as soon as you go over 14.7 psi or over 1 bar. If your Trims are different between the banks you may have a dead or extremely sleepy o2 sensor that may need to be changed

Dirk, Under vast majority of part throttle driving I am not boosted. I could probably drive all day and not pull the charger online. Under these conditions I'm running just like a normally aspirated. What am I missing? VE tuning as suggested in this thread wouldn't work? Once I go boosted I'm basically in open loop based upon the scans I see. I would think that my goals would still be the same as NA. To get the LTFT's slightly negative and tune Full Throttle with Wideband and goal being 13:1 A/F.

My LTFT's are still screwed. Don't want to hijack this thread. I've replaced 02's and fixed and exhaust leak and still no luck. gonna pull up my old thread and post questions and such to it again.

Thanks for the input.... keep it coming... set me straight if I don't have a clue.... I don't.

[S2002S]

... Matt you are out doing yourself but I for one greatly appreciate it. You have expanded my programming experience 4-fold. Keep up the awesome work but don't forget to take some time for yourself man. We'll still be lurking about when you figure it out so you can teach the inexperienced. I will keep playing with it. THanks to all again...

That goes for me too. Thanks!!!

[cured5.7]

Hey KySilverado,

Cant help with your LTFT's, but in my opinion ( correct me if i'm wrong anyone), you should be striving for mid 12's on your wide band under full noise to reduce the possibilty on running lean and subsiquent KR occurring.
Normally aspirated engines like low 13's, but forced induction should be slightly lower.


Mark

[Confused1]

Could someone clarify the correct way to disable the codes 101, 102, 103.

Do you Under the DTC'S tab

(A) leave the SES Enable On and change the Error mode to 2- No MIL Light or 3- No error reported??

(B) change SES enable to Off and leave the Error mode 1- MIL on second error??

[corpsvette]

Hey Confused,

I too was confused. ;D Here is what Matt sent me and it works except for code 0068. Not sure about that one:

edit>engine diagnostics>DTCs> use the drop down box to drop down to codes p0101 0102 0103, click the 2 no mil light button for all three, save the tune and reupload. That should take care of the light.

Hope it helps.

Jim K.

[jonmalibuss]

I started to tune my truck by the dirrections written in this section of the forum I left the ltft's on and copied the high octane table to the low and followed all dirrections and tuned till my #'s were with in 10% then I figured I would move on to the next method and shut off the ltft's and just tune with the stft's when I got some data after driving around I now have numbers ranging anywhere from 0 up to -18 but mostly from around -11 to -18.
Should I continue this tune and do as it says to use these #'s in a 1:1 ratio in the VE table or could I have done something wrong? I have been reseting fuel trims as it says to. I have not turned off the ses light because I figure it doesn't matter to me I know why it's on. one last question is this a good way to tune then plug the MAF back in? or is this only for MAF less tuning?

[Confused1]

Thanks for the help corpsvette.

I did the SES Enable On and change the Error mode to 2- No MIL Light for all three codes and saved then loaded the file . However the "Service Vehicle" light is coming on not the "Check engine" light. I checked the DTC's with the scanner and it list the 0102 code. Cleared the code and as soon as the engine is started the "Service Vehicle" light comes back. Any suggestions??

Hey Confused,

I too was confused. ;D Here is what Matt sent me and it works except for code 0068. Not sure about that one:

edit>engine diagnostics>DTCs> use the drop down box to drop down to codes p0101 0102 0103, click the 2 no mil light button for all three, save the tune and reupload. That should take care of the light.

Hope it helps.

Jim K.

[rattle]

service vehicle has nothing to do with pcm,

you may have a burnt out headlamp or tail lamp or bad ambient light sensor etc.....you need to check codes in the body control module

[corpsvette]

Hey Confused,

Actually I am getting the same thing. No SES light but on the DIC I am getting the Service Vehicle Soon warning. Is yours a newer vette by chance? I have posted elsewhere but I have not received an answer yet. Rattler, I have to disagree(not with your reasoning) with you on the cause for what we are experiencing because if I plug the MAF back in, it goes away and reappears as soon as I disconnect the MAF again. How would we check the BCM codes....through the DIC? THanks,

Jim k.