Needing a little help with MAF tune.

[Moistbread]

Currently trying to tune my 02 Silverado 2500hd and although iv'e watched goatropegarage and multiple other MAF tuning videos im still at a complete loss. I'll take the truck for a WOT drive but it has almost feels sluggish between 2.5-3.5k. i keep Paste special % -halfing my AFR Er but i seem to be just stuck in a loop with the calibration testing. is there something i missed or should i just keep driving and modifying the tables. Thanks you guys i don't want to bug but desperately needing help. any chance someone can just take a look and give advice?


02 Silverado 2500hd 6.0
212/218 .553"/.553" 113LSA
560" springs
stock pushrods
stock headers
aftermarket int

[5FDP]

Are you doing your AFR error stuff with the fuel trims still active?

I'd change up your power enrichment settings so they don't have massive delays as well. Lower the hot/cold throttle enable to 65%, remove the 60 second time delay and set the rpm delay to 1,500. Also raise the MAP kpa enable to 80 and lower the enable torque to 50%.

That will help it bring fuel in faster and should be more responsive.

[Moistbread]

no i currently have DFCO, Cat protect and STFT LTFT off. and thanks will do right now! see, these are the things i figured the videos didn't talk about.

[5FDP]

The tune and log show that they are on, that is why I asked.

[Moistbread]

oh wow. i completly didnt notice closed loop was active on this run. ill do another here in a sec lol. i was using another safe cam tune but it was throwing me at 16 afr so i stopped and put my "Safe" tune in and didnt notice. definitely a hickup.

[5FDP]

You mean closed loop.

Turning off short term trims and long term trims puts it into open loop.

[Moistbread]

sorry about that. just went out and did a run with the enrichment and everything you said. including making sure i was in open loop. just seems like one run ill be lean 8 percent in a cell then after paste special -half ill be rich 8% on the next lol. and yes, my lambda reading is wrong, iv'e troubleshot it a few times and still wont correct itself.

[5FDP]

Add your throttle position to the logs, hard to tell what that is doing without it in there.

Careful with your fingers, you put 552kpa in the PE kpa enable instead of like 80kpa.

When I tune the MAF or VE I an doing long data logs. Like 20min at least to get as much data as possible. I use the paste special and then hand smooth the curve or the VE table. It's never going to be perfect and if the fuel trims are only doing +/- 5% afterwards that is good enough for me.

[Moistbread]

ahh i see it was set on 80 PSI and not kpa. Ill add it and run again

[Moistbread]

dude you are a legend. that simple PE fix opened her right up. now maybe i can get the MAF calibration right. Thanks!

[5FDP]

Well it fixed one problem and now shows another.

In the log your knock retard maxed at 8 degrees. Usually that either because somehow it's really knocking that bad or you have a pending or current knock sensor code. If a code is present the computer will default to the max timing pull that is set in the calibration, which on this one is 8 degrees.

With that amount of timing it's yanking out, that is a lot of power being taken away. Once that is fixed it will feel even stronger when it's not running 0 degrees of timing at full throttle. You should easily be able to see 20 degrees on a NA 6.0 with a mild camshaft.

[Moistbread]

Alright, I just last week replaced both faulty knock sensors. I have not moved the spark table and it has 87 in it. I?ll double check the codes but currently it only is showing my EGR fault because i havnt deleted the code.

[Moistbread]

yeah just to make sure i did another small pull while out. definitely pulling all the way down to -1 timing for some reason. maybe crappy gas? having a hard time wondering why it would only show knock at WOT. So, your saying i should technically beable to be in the 20 area? dam thats a hell of a lot of potential

[5FDP]

The log shows a P0327 code for knock sensor. Did you replace the harness along with it?

I've seen the codes come back with non OEM sensor and or a bad harness.

Only a select few times have I needed to turn the codes off even with new parts to stop the timing pull. I tested the knock sensors even with the codes off by smacking the block with something to see if the knock sensors still picked it up.

[Moistbread]

yes i did replace the harness as the old one was destroyed. ill do the knock sensor test tomorrow by banging on the block. i did replace them while the intake was just pulled up not actually off so maybe bad connection? and yeah i need to do longer logs but with it pinging extreme afr i didn't want to take the chance yet.

[Moistbread]

Alright tore the intake off and behold the front knock sensor must of never been clicked in fully because it came right off. took it for a run and no knock! well it did pop 1 at WOT but definitely was the issue. now maybe i can actually get MAF dialed in then work on timing. thanks again 5FDP!