INput needed for my tune. Im new to this but diving head first

[jaybuller]

Good Evening Guys, I am new to HPtuners.
I just finished rebuilding my 2004 2500hd engine. I did a stock rebuild with the exception of porting the heads and adding a cam and springs.
The Cam is a BTR stage 2 truck cam. Specs on it are 212/218 .553/.553 111LSA. the rest of the engine is stock specs, I hand ported the heads mostly just smoothing the chambers and polishing the castings up inside to flow smoother.

I used my stock file to modify and have only changed a few things to help idle. (bumped timing in the idle ranges up to 25 degrees and changed the base idle airflow to around 12-13) its idleing pretty good now and i can drive it around and it seems to do good. Can yall please look my tune over and my data log to tell me where i can improve? My LTFT look high and off to me esspecialy when im getting on it at mid to high rpms.

[jaybuller]

i will also be installing an aem wideband with prolink as well in a few days. so hoepfully i can figure out how to use that to improve things

[twenglish1]

Any changes to injectors or fuel system? This will need tuned due to the changes listed, make sure injector data is correct, then fail MAF sensor and use fuel trims to adjust VE table, you will want to add more scanner channels too, manifold pressure, short term and long term idle trims(P/N and Gear) for adjusting base running airflow. Should also add spark advance, and Knock Retard as well

[jaybuller]

Sir, no the fuel system is completly stock including injectors.
Okay i will try and figure all that out! Adding those scanner channels shouldnt be too hard.

Im not exactly sure how to use the fuel trims to adjust the ve table but hopefully i can figure that one out!

[twenglish1]

No changes to engine displacement either? Updated your file by disabling the MAF sensor, this will force the PCM into speed density fueling mode.

2004 2500hd - MAF Failed.hpt

Use the compare function with this file and your original file if you'd like to see what changes have been made

[jaybuller]

no Sir stock bore (ball honed and new hastings rings on original pistons.) Thank you ill try that out

[twenglish1]

Set up a chart to plot LTFT+STFT against MAP and RPM, make the row and column headings match the VE table, this will plot your fuel trim correction percentages onto the chart that can be directly applied to the VE table.

Screenshot 2025-02-13 194514.png

[jaybuller]

No changes to engine displacement either? Updated your file by disabling the MAF sensor, this will force the PCM into speed density fueling mode.

2004 2500hd - MAF Failed.hpt

Use the compare function with this file and your original file if you'd like to see what changes have been made

just to make sure im seeing this right... (you changed the high rpm disable from 4000 to 9000 rpm in the dinamic airflow tab?) thats all i could find.

[twenglish1]

Under "Engine Diag" MAF frequency fail high is now set to 1, this will set the MAF DTC anytime MAF frequency is higher than 1, which is always when the sensor is hooked up. Then under the DTC tab of Engine Diag, MAF codes were set to MIL on first error, this will set a MAF DTC and force the PCM into speed density mode

[jaybuller]

i sure apreciate you taking the time! I have it all setup as you sugested. tomrrow ill go run it up and down the road data logging with that setup and the maf failed.

I kind of think i have the gist of what needs to be done with that data. (copy the data from the scanner over into the ve table in the editor do paste special multiply by half then interpolate the blanks) then write that tune back into the vehicle at least thats what i think i need to be doing. haha. then go into the scanner and go to special functions and reset the long term fuel trims.

am i on the right track?

[twenglish1]

Yes you are on the right track, try to hit as many cells as possible, make sure to use the smooth functions too, no wide open throttle/PE until you get a wideband installed, dont want to cause any damage

[Lshungy]

Also try and make the drives as long as possible, you need to average out the trim percentages . Try a higher cell count if you need . A cold or warmed up engine will make a difference and also transient throttle changes too can sway readings. So hence twenty’s advice on smooth driving .

[jaybuller]

Set up a chart to plot LTFT+STFT against MAP and RPM, make the row and column headings match the VE table, this will plot your fuel trim correction percentages onto the chart that can be directly applied to the VE table.

Screenshot 2025-02-13 194514.png

I setup my chart as is in your screen shot. My one question is in the filtering function block you have ([50010.242] > 130)

what is that for and do i need to do type that in there as well?

[jaybuller]

i sure will take that advice. I have to go to town (about a 30 mintute drive on back roads) itll be quite the long drive and ill keep the driving smooth as i can.

[twenglish1]

I setup my chart as is in your screen shot. My one question is in the filtering function block you have ([50010.242] > 130)

what is that for and do i need to do type that in there as well?

That is just there to make sure its warmed up before logging trims, thats the pid for coolant temp

[jaybuller]

Thank you. So I just went and logged. However on that Ltft+ stft log it only logs in the 15 kpa blocks at the top.
But on the ltft only log it filled in all the boxes.

[bk2life]

Thank you. So I just went and logged. However on that Ltft+ stft log it only logs in the 15 kpa blocks at the top.
But on the ltft only log it filled in all the boxes.

can you post a picture/screen print?
also, the log, so we can see what your missing.

-when it doesnt log correclty, there is usually a channel missing, or incorrect selection somewhere.
....and its a computer, sometimes a simple restart is all thats needed to fix any issues.

a long drive it nice, but, dont drive from start to finish at 45 mph. there will be hardly any data logged.
You need to drive from idle to lets say 55 mph ( i stay under 3k during this time) and vary the throttle to fill all boxes.
soimetimes driving with foot on brake to load up the engine to simulate going up a mountain

[jaybuller]

graph for Tuning with MAF disabled (LTFT + STFT tuning).Graphs.xml

[jaybuller]

any chance you can see that? i am sure trying to get a screenshot butltft + stft math.jpg

[jaybuller]

LTFT 1.jpg