Tuning my 04 suburban quadrasteer

[quadraburb]

Hello,
Been a lurker for a while, first time posting.

I'm working on getting a freshly built motor in my 04 suburban to run. its a pretty conservative build: stock 6.0 LQ4, a BTR stage 2 truck cam, 317 heads, and a Dorman 615-183 truck intake. I know these trucks almost max out their injectors and I have a set of 50 lb flex fuel injectors to go in but right now I just want to focus on the small stuff and get comfortable with the program.

So far the truck starts up, runs, holds a steady idle, and drives without needing pedal or help. I set the idle up with suggestions I saw around here as well as some other places, namely idle increase and timing as well as airflow. But its mostly all ballpark figures I need to fine tune.

I'm working on getting my wideband hooked in today and working on part throttle tuning, attached is the current tune if anyone wants to provide feedback.

[quadraburb]

Went out and did some MAF scaling today.
took me some time to figure out how to the get the AEM wideband to attach lambda output to EQ ratio and then run that through MAF frequency and EQ ratio. did about 10 runs, working my way up to about 70% throttle, each time applying data by paste special and multiply by 1/2%. had to pull some ignition out in a few areas but after a while you could feel it responding better and staying spot on with fuel.
After a while I got it reading within +/- 1 to 1.5 through most of the cells and the MAF curve looked pretty smooth so I added it to the primary tune with VE enabled and it fell on its face and went pig rich at idle as well as started throwing maf circuit codes.

Reading up on what I'm dealing with before going further, I may be adding too much data to the curve at one time and should scrub through it in smaller bites. attached is the latest tunes. MAF run 10 and the primary tune with the scaled MAF added. unfortunately the logs got saved to temp and the computer trashed them, that was my mistake.
I'm tuning with the Wideband in the bank 1 factory spot, which as I understand disables the LTFTs, but just to be safe I disabled them in the maf tune as well.


EDIT: it throws a p0101 code when it falls on its face, which says theres a difference between the MAF and VE tables and it falls into SD to check if the maf is the problem.

I put it back to a copy of the as found tune and loaded my idle changes, it still fell on its face and threw a p0101 code. but if i load up the maf only tune files it runs great again.
User error is hiding somewhere.

[quadraburb]

I got it backwards. started with MAF, and should have started with VE like the old megasquirt days.

this thread helped https://forum.hptuners.com/showthrea...af-tuning-help

tomorrow I'll go work on SD and see if it correlates with the MAF curve then see what happens when I plug them both in.

I'm troubled as to why its still falling on its face with the before maf adjustment tune on, but it also can't go into LTFT since the wideband is plugged in where the bank 1 O2 goes. so that may be my reason.

[5FDP]

The open loop STFT need to be turned off too with wideband tuning. It doesn't matter if you tune the MAF or the VE first, people can do it either way.

[quadraburb]

The open loop STFT need to be turned off too with wideband tuning. It doesn't matter if you tune the MAF or the VE first, people can do it either way.

forgive me if i missed something obvious. but I swore I had STFT off, it was showing all zeros on the log as I was scanning.

Edit, found it. right under my nose.

For the google searches:
Disable LTFT: Engine>Fuel>Oxygen Sensors: max out ECT v IAT table and temps
Disable open look STFT: Engine>Fuel>Open Loop> STFT open loop = Disabled

Thanks! will re-attempt tomorrow.

[5FDP]

There wasn't a log posted, so I just wanted to point that out because I couldn't see it.

[quadraburb]

corrected mistakes, disabled open loop STFT and went for another MAF tuning session, then switched to SD and gave it about 6 runs.
with the combined graphs the truck is running a lot better and manages to get out of its own way. lots more work to do on some upper areas as well as going in by hand and smoothing out the VE table
got some knock around idle getting going. looking through the data right now. but the way forward is pretty clear now. just need to get it 90% dialed in, go up to the bigger injectors, repeat the whole process, and then get it to the dyno for someone with more experience than me to chip away at.

[quadraburb]

its been a while, i travel for work. but I've had more time to work on the truck. figured I'd update for the search engines and people looking for similar setups.

I did about 180 miles of tuning on the VE and MAF scaling. the truck responds a lot better, but i still have the timing dialed back slightly. not willing to touch it yet until I've got a good understanding of the knock sensor tuning and if i can trust it in this truck.
I have time slated with someone who has a dyno and does more work than i do at the end of the month, but for now the truck is running just fine. no knock, a little shakey on the LTFTs still, about 8-12% sometimes. but im still chipping away at it.
i also welded in a bung to install the wideband WITH the narrowbands so i can easily switch from scaling tunes to full running with LTFT and just see how its working in closed loop.


I went ahead and updated the injectors to the gen IV flex fuel injectors, PN 12613412
These are pretty much drop in with the LQ4 except you need to swap the injector harness to USCAR style male end plugs. its a worthwhile upgrade even for a stock 6.0 by my research.
I also had to dig up the injector data because they're larger and the computer needs to know how much fuel its putting in.

inside the attached tune is the injector data that I've manage to find for the 12613412 injectors. there are two threads in this forum that have differing data in txt format but loading them in the tune caused erratic behaviour.

going out for more MAF and VE tuning today.


the only thing bothering me is one lifter has developed a quiet tick from 2000-4000 rpm. i've read its normal for the LS7 lifters on 5w-30 but its still obnoxious.

[TowinDaLine]

I have a subscription to this thread, as I have an '03 GMC 1500HD with QS. So thanks for updating -- I can promise you that *someone* is reading your updates!

My build is much like yours, and I have the same injectors / adapters ready to swap in. With the stockers, I got them as high as 97% duty cycle at WOT (just for testing).

Will look through your tune with some interest; I noted the discrepancy with the injector info, as well (one reason I haven't jumped in and done it already).

FWIW, I've read info that the 3rd gen knock sensor (in the valley cover) is actually better, performance-wise, than the relocated 4th gen ones. So if your sensors were refreshed, I'd put a little faith in them. Haven't run across KR yet, but like you, I haven't touched the timing yet, either.

Like yours, mine is running well right now (and the cam is a tow grind, so nothing radical).

I do still need to hook up a wideband and fine tune it (was debating whether I should do that before the injector swap, and I probably will, just so that I have a good baseline before swapping the intake / injectors.)

Your post will entice me to put the truck back in the garage and start working on her again, so she's ready for spring. Just got through rebuilding the Dana (carrier bearing was chewed up; I freshened up all the other seals / bearings while I was in there). Mine's a dedicated tow rig, so she's not driven much. I do have 'stage 2' plans for her, but won't go into that right now (it'll be 'next' winter's project, after I get a season's towing on her with the mods I have now).

[quadraburb]

I have a subscription to this thread, as I have an '03 GMC 1500HD with QS....

I come from the world of syclones where we're still tuning with dipswitches and rom reflashes. the syclone is incredibly notorious for false knock, to the point that its killing my 1/4 times when its just a fuel line thats rattling a little. every so often the burb throws maybe 5-6 degrees of retard but its transient and never under load. i had the mic on it and heard absolutely nothing.

I got the injector swap and programming done in two hours. all you really need to do is tell the ECM how much the injectors flow, and it does the rest. I noticed I was running about .3-.5 lambda high under transient load with the new injectors but about 50 miles of tuning and it was back to stoich and running predictably.

I've done a rebuild on my burb already with the rear end. make sure you change the rear end oil religiously. the rear steering is hell on the trac-loc clutches in the carrier. my brother shelled his carrier, and bought the last one yukon gear had in stock at the time. these things are getting harder and harder to find parts for but they tow like a dream and handle like my civic.

I mounted a wideband right under the transmission oil pan with a no weld bung clamp. its too cold and wet out to wrestle the suburbans inhumanly huge exhaust out to weld a real bung in and this works well enough. no leaks.
its too bad the speed engineering headers dont fit this truck. the crossover pipe and cats are entirely different on the burbs. no one really makes anything and i dont have the time to fabricate my own.

[TowinDaLine]

I've done a rebuild on my burb already with the rear end. make sure you change the rear end oil religiously. the rear steering is hell on the trac-loc clutches in the carrier. my brother shelled his carrier, and bought the last one yukon gear had in stock at the time. these things are getting harder and harder to find parts for but they tow like a dream and handle like my civic.

Yeah... I found out firsthand (thanks to prior owners). I'll keep it brief, so as not to hijack the thread.
The really tough part to get for them was the rear steer position sensor, but it's been reverse-engineered, and they're now available again from gooodsystems
(3 'o's -- not a misspelling). The CV axle for the 8-lug is also hard to find now (the 6-lug versions are too short to interchange, which I also know firsthand)

Good luck w/ your tune, going forward. ::thumbsup::

[quadraburb]

Did a 1000 mile journey from where I live to scranton and centralia and back. got a lot of stuff ironed out including PE, most importantly. the VE table is starting to smooth out and I'm noticing why GM included "flat steps" on the stock VE table, it looks as if thats where 3rd gear and overdrive like to hang out when cruising.
I've been working on adjusting the VE table by hand to smooth it out for better response. some of the areas are still crappy, and theres missing zones I need to push into but I'd rather do that once I have the core running areas safe and stoich.

PE was temperamental to get going. I had to zero out almost everything except the minimum map so it would refer to just the throttle map. I also zeroed out the ramp in point but I'm going to start adjusting that because I dont like it just slapping fuel down instantly. But its working now, and it doesn't try and make power entirely stoich under load now. I have it adjusted to make about .80 lambda but thats on the rich side for a mild build. I've read about .83-.85 is where you want it for max power but one thing at a time.

Unfortunately, it seems my front hubs are going bad, and the rear differential needs inspected too. so I'm hanging the tuning up to work on the diff, and then focus on my audi allroad im building as well. for now the truck is running safely, no knock, despite some questionable areas, but I also drive pretty lightly on it.

attached is the most updated tune, with the PE on and the trans maps from an 05 yukon added which seem to perform more responsively and eliminate some issues I've long had with the truck and shifting. I have bluecat but I'm not about to start messing with it right now.

[quadraburb]

Rear diff checks out, grinding was from front differential carrier bearings. so 2WD it is.
I played with the MAF and VE tuning today and started messing with knock counting and working on the timing.

Theres a few almost WOT pulls in this log, and attached is the latest tune.
in one area the knock confused me, i was getting off the throttle and it was retarding timing and it knocked by a few degrees. looks like legit knock in my limited experience too.

I think the VE and MAF need a lot more work before I dig into any more timing work so I've gone back out to do some scaling runs.
any input?

[gagliano7]

How does the suburban feel with the 6.0 compared to the 5.3? I also noticed your WOT timing is really low. Once you get that dialed in it will make a big difference. When i upgraded to the 50 lb injectors i didn't have to change anything fuel wise. Don't know how much of a difference it makes but my default injector pulsewidth is 1.109 and your is 0.243. My short pulse limit is 3.997 ms and yours is 3.921 ms. Everything else is the same for the 50 lb injectors.

[quadraburb]

How does the suburban feel with the 6.0 compared to the 5.3? I also noticed your WOT timing is really low. Once you get that dialed in it will make a big difference. When i upgraded to the 50 lb injectors i didn't have to change anything fuel wise. Don't know how much of a difference it makes but my default injector pulsewidth is 1.109 and your is 0.243. My short pulse limit is 3.997 ms and yours is 3.921 ms. Everything else is the same for the 50 lb injectors.

sorry, been at work for the past month, keeping 747s flying is surprisingly easy compared to cars, but it is time consuming.

the 2500 suburbans have a bit more bulk to them. I've done a few red light launches with the stock engine against a 5.3 1500 and the 6.0 can pull ahead, but its not anything to write home about. it definitely has more pulling power, though. I pull a 25 foot car hauler with a syclone in the back which is about 8200 lbs. the 6.0 happily gets going, runs right up hills at 60 mph, and doesn't really complain. but the 4L80 really makes a big difference too.

I'm starting to move into WOT tuning, I can feel its wheezing on the power when I floor it. the engine is really trying to go but you can feel the ignition is too retarded. I paid for access to HP academy to learn more about spark tuning on these, and kinda regretted it, but it is full of little details and answers to stupid questions like "why am i getting slight knock on transient partial throttle?" (its fine, its gonna happen) I'm hoping next week I'll be able to get a crack at the timing and see how it wakes up.

I think I left the injector pulse-width alone from the tune I pulled the data from, I'll have to go back and check, but I believe I pulled the pulsewidth from a gen IV tune, and the rest was from another tune on someones trans am.

The only real worry I have right now is that i'm on oil change #5, with 1400 miles, and I'm still seeing a slight pearlescent reflection in the oil. but im probably just being anal.

[MrGuy]

You did almost the exact same setup that I have, except the head choice. I plan to get a TBSS intake later. I'm still running the OEM injectors but recently ordered 50# ones. I plan to put them in when old balls Mr.Winter leaves MN and it gets above butt a$$ cold.

[quadraburb]

You did almost the exact same setup that I have, except the head choice. I plan to get a TBSS intake later. I'm still running the OEM injectors but recently ordered 50# ones. I plan to put them in when old balls Mr.Winter leaves MN and it gets above butt a$$ cold.

I stuck with the stock heads, they flow well enough for my needs. with your setup I would recommend saving some money and going for the Dorman 615 intake. its provides good results for a mid range cam like ours, and allows you to keep the stock throttle body. the TBSS intake gives good gains too but you need to get the x link cable and a new throttle body.
I'm used to line maintenance up in anchorage, I think it was 17F out when i swapped my injectors over and installed the conversion harness. couldn't feel my fingers at the end but whatever.

[quadraburb]

Back to work.

knocking has been all but eliminated under load, I'm working on ironing out the MAF and VE with respect to smoothness at this point. if its not within +/- 1.5 i adjust a bit by hand.
working on timing after that.

I also fixed an issue where it says it sees a misfire at idle all the time. with a larger cam the ECM isn't going to like the time between firing pulses. its used to a more efficient cam at lower ends that has a more predictable idle, not a lopey cam. so you can tune it to wait a little longer between pulses before it declares a misfire. at least, that is my understanding.

engine diag> misfire> cylinder mode: idle (moving and not moving)
you'll want to adjust anything thats not 32,676 by a factor of 2 according to some of the posts I read. I multiplied by 1.5 just to see how it'll affect things. you want the system to be ignorant enough to put up with the lope, but flash a problem if, say, you lose a coil.

[quadraburb]

fuel is pretty solid all the way up to redline, starting delving into timing adjustment.

I'm thinking about just scrapping the whole ignition table and using whole values instead of using whatever the matlab function GM used generated. its confusing to try and isolate problem areas with decimals everywhere.
I raised the timing up by about 5 degrees in some areas, and that really woke it up. but i went too high in the mid range, had to back it off by about 3 degrees in some areas. the map is a mess and I'm still learning about the best way to go about adjusting ignition. so for now I set everything back to the way it was minus the fueling adjustments and I'll start working on generating a base advance map.

for the rest of the day i've been working on DFCO tuning based on a thread ECtune had going where mileage can be increased slightly with better settings.

[quadraburb]

Made a LOT of adjustments.

firstly, adjusted burst knock and detection sensitivity which all but eliminated the high knock numbers that came out of nowhere.
then I went back and used the stock ignition table and raised it up by a percentage.
I also went in and redid torque management, abuse, and power enrichment timing.
went into the transmission tab and adjusted pressures and shift scheduling based on another thread I was reading.
I also redid my idle spark correction, its a lot smoother but I miss the lope.


and then went out and did some timing adjustments. things are running much better now in terms of knock. when I see knock I actually believe it now.

attached is the latest revision. if it looks like im going in the wrong direction please let me know, im starting to feel good about this, which is when I start to get dangerous.