first attempt at tuning...got some questions. Something doesnt seem right...?

[dhirocz]

So I'm trying to tune my 11 6.0 Silverado and get it decent enough to make a trip to the dyno and get it dialed in. Truck norris cam, CNC 317 heads, longtubes, ported TBSS intake.

Ive adjusted the engine size and the injector data is correct according to the data I have for 50# flex injectors. I pulled a few degrees of timing from the base table and started with MAF tuning (it was running extremely rich) and got it alot closer than it was. I had to disable the O2's by manually unplugging them and turning off the codes, also disabled COT, and dynamic air. I'm tuning using an AEM WB, and I thought I got it pretty close so I started trying to clean up the VVE table.

My VVE adjustments seem to me to have been rather minor. I noticed I start having what sounds like a lean pop in the intake so I turned the MAF back on and went back to MAF tuning and the tune was again off. I noticed it I let it idle long enough, it will eventually start going lean while I'm running the scanner. I also noticed that some cells in my EQ ratio error histogram will want several precent more fuel. When I do it again, it'll want several percent less.

I noticed my MAF hz is around 3700 at a 725 RPM idle which is higher than some other peoples engines (engine size maybe?) but I wonder if its an issue...my CAI has a plastic cone inside (doesnt fit real well at that) just before that MAF that reduces the intake tube diameter but also biases airflow towards the MAF sensor. This insert is removable and I'm wondering if this is intended to be used for smaller displacement engines. I can't find anything on this, and am not sure if it's a good idea to remove it.

Maybe i'm overthinking this? I'd like to figure this out before I spend too much time trying to make it run better with the current cost of gas. If I'm going to do that I might as well put on the ported TB I have as well.

It is at least drivable. Its definitely better than it originally was. It still likes to pop under high load low RPM situations between 1400-2000 RPM. Here's a copy of the current calibration if anyone wants to take a look.

Far from the first engine I've built, but I'm just trying to build a basic skillset in tuning with the intent to create a safe tune until I can get it on a dyno and have it dialed in. I haven't done much yet with timing on it, havent gotten that far yet.

[dhoagland]

Post up your logs

[dhirocz]

I?m having a hard time getting a good log. Right now I?m struggling getting consistent readings. It?s going significantly lean out of nowhere while cruising. I did pull that insert in my cold air intake out, I?m going to put it back in and see what it does.

It seems to be rather crazy that there is something like that in my cold air intake that would choke the hell out of the engine.

I reverted to an older calibration thinking I might have screwed something up in a table somewhere, but it still goes gradually leaner and leaner on its own.

[dhirocz]

So I put it back in and the stupid thing immediately had an effect on the AFR. I wonder if that can be removed, as a bottleneck in the cold air tube has to be awful for power. I?m going to try to pull a log and see it it stays consistent or if it starts leaning out again.

[GHuggins]

O2's still unplugged? If so plug them back up and then see how it does. Sounds like it's doing a cat test...

[dhirocz]

O2?s are still unplugged, COT and dynamic air as disabled. Doesn?t look like I can get it closer than about 2 percent. Maybe I should try putting the WB in place of the O2 instead of the bung in my Y pipe. I?m about to try VVE again.

Wondering if WOT is a good idea or not since VVE and spark are still out of tune under the circumstances, but I don?t see how else I?ll get all the data needed for the MAF table otherwise.

[dhirocz]

OK so I spent a few hours with it today.

I canned a handful of my last tunes and went back to MAF tuning. Didn't have too much of a problem, a couple of minor lean pops but I got it within a couple percent after a few iterations of my target AFR.

I noticed once I got close, it started richening itself again on it's own. I decided to stop there since the last time it did this, if I let it stabilize and saved the data into the MAF table, it would end up rich again a similar amount when I started it up, almost like it didn't appreciate being that close to spot on. I took a quick log of this at an idle as I was afraid to tune MAF further at this point. It will continue to lean out if you let it.

new1.hpl

At this point, I failed the MAF and its associated codes (02's still unplugged and codes turned off, COT disabled, dynamic air disabled) and proceeded with trying to straighten out the VVE tables somewhat. They started off by being 10 percent or more off. I got them within 2 percent...no indications of a problem...then all of a sudden after the 5th correction, it went super lean (upwards of 50 or more percent under a light load). I caught it at an idle, but it was significantly worse while under a load. I coasted to a stop, and while not under a load it went back to stoich.

newidle2.hpl

...I decided to reenable the MAF, take it home and shut it down for the day.
I haven't been able to find a reason for why it wants to go rich out of nowhere like that. I'm assuming I'm either missing something, maybe there is something I failed to disable, or maybe there is an issue with my WB 02 sensor. I can say that when it starts going lean, I get a flashing SES light. Only code I've managed to pull under that is a P0506 (Idle air control system RPM lower than expected) but it tends to happen when it's lean so I'm leaning towards my inexperience in tuning.

Somewhere in this mess, my idle instability issues came back. Probably when I went back a few calibrations. Ugh.

I'll never complain again how much it costs to get a good tune, lol...

This is the last calibration I had in my truck tonight.

base_silveradonew13.hpt

[kevin87turbot]

Out of curiosity, what brand CAI are you running?

The VVE tables are a mess...and they don't match. There's a big tower in the middle of the Manifold Switch Closed VVE. The Manifold Switch Open VVE doesn't match it. Are you just changing one of the VVE tables?

The MAF table doesn't look too bad though.

HP Tuners VVE Table tower.jpg

[dhirocz]

I do not understand why that spike is there. Like I said, when it acted up, I turned the MAF back on and stopped for the night.

Perhaps that was the area I was working on when it leaned out? Looks suspicious though.

I was working the closed VVE table. I was going to copy it over to the open table when I was satisfied with it.

CAI is a speed engineering piece. Mostly just a pipe and couplers, other than that insert I mentioned a few posts back that caused me some grief.

[kevin87turbot]

I do not understand why that spike is there. Like I said, when it acted up, I turned the MAF back on and stopped for the night.

Perhaps that was the area I was working on when it leaned out? Looks suspicious though.

I was working the closed VVE table. I was going to copy it over to the open table when I was satisfied with it.

CAI is a speed engineering piece. Mostly just a pipe and couplers, other than that insert I mentioned a few posts back that caused me some grief.

You can't tune the VVE tables like that. Honestly, you'd be better off to start back over with the stock tables. When you do, here's the procedure...

Make the changes to the Closed VVE table, then click the Calculate Coef tab. Next, copy/paste that table to the Open VVE table, then click the Calculate Coef tab.
Rinse and repeat as necessary. I always take a look at the tables using the 3D graph button and make sure they are smooth.

[dhoagland]

Not sure if this matters, Just a few thoughts..

You still have the Tune going into closed loop after 36 degrees (I know you have o2 unplugged) But I've been taught to set tune up for open loop tuning you max the value in the attached picture

Maybe even with the o2 unplugged its trying corrections in the background

Also
Are you familiar with Rich after Flash?
I see you have injector tip temp zero up pretty high in the scale, but something to think about

Intake Valve Temp can also cause swings
Might want to log these 2 just to see where your at while logging

[dhirocz]

I am not familiar with rich after flash. I’m also not seeing anything about intake valve or injector tip temps. Im trying to read up on that now. I feel like my head is swelling but I have to admit it would explain some of what I was experiencing. The engine that was in the truck was an LC9 but it was replaced with an iron gen IV LY6 shortblock so that might explain some discrepancies in the tune as well.

Are you saying that even though the scanner says it’s in open loop, it may still be attempting adjustments?

I found a hole in the hose going to the passenger valve cover from the cold air tube. How, I’m not sure, but it’s not going crazy lean now. It’s not perfectly consistent in its readings but it’s much better than it was. I did a couple iterations of SD tuning and some more MAF tuning today. Definitely needs more tuning but it's at least drivable and not super rich (or lean)

[dhoagland]

The Screen shots show:
Injector Tip Temp Gain in your Tune file
And 2 Open Loop tables that show they adjust fuel based on Intake Valve Temp and Other parameters

You can Log those in your scanner and see where your are running.
It is possible you could be logging/adjusting in one range, then as you drive enter another range things cool down and you go leaner.

The Rich after flash is based off Injector Temp Temperature and when you reflash it defaults to a value based off engine coolant temperature (Lets say its 200)
So if you look at the injector Tip Temperature gain (added injector pulse width to compensate for heat soak) you will be running rich and as your Tip Temp comes down, while you are driving, you will lean out
I chased my tail on this MAF tuning when I started, got very discouraged until I learned not to log until things stabilized

As for it trying to adjust fuel even though the scanner shows Open Loop. I'm not sure if its possible, but setting it in the tune where it can't (or shouldn't be able to) is kind of taking a variable out of the equation

[dhirocz]

I see. Got more work to do before the next round of tuning from the looks of it.
I also have a new task. Try to find out why I have a P216A for AF ratio imbalance. Bank 1 is apparently running 10% richer than bank 2. This happened after I turned back on DFCO and the 02’s so I have some homework tonight.
Since practically everything is new on this engine except for the coils (which I have already had to replace one on bank 1 for an occasional misfire) I'm going to start there before taking it out for tuning again.

[dhirocz]

Problem was the injectors. It didn’t like the L96 injectors. They were supposed to be new, but I’d bet now they were knockoffs. I was getting different temps from cylinder to cylinder on the header tubes by over 100 degrees.

I swapped out a couple questionable coils and switched the 02’s and no dice. Rescaled the injector table and put the LC9 injectors back in and now it’s solid from bank to bank. And it’s asking for less fuel to boot.

Tomorrow I’m replacing the lighter socket (it burnt out) and it’s back to tuning tomorrow. I’m starting all over again.

[dhirocz]

I've been able to get things dialed in a bit closer with the engine being more consistant. I can say I'm running upwards of 90% injector duty cycle at WOT. I'm so far satisfied, I've been able to add some spark and the engine has responded very well to it.

I have had a couple questions I need to ask while I dial this thing in.

I still have idle surge, mostly in P/N. It's less with the A/C on and when it's in gear and is mostly a minor annoyance. If I leave it in P/N it will eventually stall. I've tried playing with the minimum airflow and idle spark and cant seem to make it happy under 1000 RPM. When it's cold after I get it running it idles vaguely decent until it gets to about 160 degrees when it starts to oscillate and eventually stalls. I must be missing something. Log is here: idle maf.hpl

This next one is a question of strategy. When tuning MAF and SD, I noticed an odd shape to my VVE table that I'm assuming is due to the different gears in the 6L80E. It makes sense as the load changes depending on the gear that I'm in, but wouldn't that make it harder to dial it in? Also seems to me that it would also play hell with MAF tuning for the same reason. Up to this point I've just been driving it and changing up the speeds, holding gears and changing up the throttle input (especially with SD tuning) to hit as many cells as possible.

I did log some KR while I was tuning SD and realized that I was still in SD...no MAF, no 02's. I'm going to go out on a limb here and ask if the ideal way to tune for KR/spark is with the VCM configured with everything operating (MAF, 02's, dynamic, etc)? I've been limiting time over 4k since I'm not yet familiar with handling tuning in PE.

Am I on the right track, or...?

Current calibration: silverado_LC9inj_SD10.hpt

[kevin87turbot]

I don't see the wideband data in that datalog. How close is it to stoich?
Where is the wideband sensor located?
Just make sure it's dialed in very close to 14.7:1 at idle and cruise conditions.
After that, you can enable closed loop again and see what happens to your idle.
I'd also put the over/under speed timing tables back to stock.

Your manifold switch closed and open tables are oddly shaped...and they still don't match.

[travisty75]

I have to preface my response by admitting that I'm new to this myself, but this has helped me dial in my idle to something I'm happy with.

Log your Idle Adapt Advance. This will show you how much the spark is attempting to control the idle. The more it steps in, the more your airflow is off. To me it looks like your base running airflow is higher than it should be. The Spark Over/Underspeed is cutting spark quickly, then pulling closed the throttle blade, then as the RPM drops the spark comes back in to pick it back up. It ends up oscillating because they're both overreacting.

Regarding MAF/SD logging and the gear changes, what are you using for filters to remove the transients and gear changes? This post discusses the importance of filters, and the Excel file found in this reply in that thread has some excellent examples. Without filters like the ones in that thread (or this post), your data will always be skewed and include information you don't want your MAF/VVE table to be based on.