l83 idle in gear

2016 silverado 5.3l A6 with texas speed stage 2 (218/226, .635"/.635", 113 LSA, 10% fuel lobe). trans was rebuilt back in Dec. Torque converter was replaced with a billet stock stall speed. Keeping it until their warranty is up and going with a higher stall.

Im trying to figure out if the issue im having is tune related or the torque converter. idle in park/neutral is fine. has a nice quick little lope. As soon as it goes in gear, idle smooths out and the exhaust seems to get louder like its TM advance. On coastdown coming to a stop you can hear the lope and as soon as you stop, idle smooths out again. it didnt always have this. i either have a scewed table or something is going on with the converter. or i could be worried about nothing.

Hoping someone can point me in the right direction.

the log i have is short going from park to drive a couple times. im logging a shit ton of stuff. ill clean it up and get a better log tomorrow. the tune is a maf only tune to check on fueling on the maf side.

thanks!

Why do you have your Rpm set to 700 rpm's in every tab????? Does it crank fine when it's warm? I have that same cam in my L86 and it would crank and stall with that low of RPM's if it was warm. But my cold start is much higher than 700 rpms and I would it would stall there to it I had it set to 700

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Originally Posted by Jonblarc7

Why do you have your Rpm set to 700 rpm's in every tab????? Does it crank fine when it's warm? I have that same cam in my L86 and it would crank and stall with that low of RPM's if it was warm. But my cold start is much higher than 700 rpms and I would it would stall there to it I had it set to 700

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I actually just lowered it from 750 but it cranks fine while cold or warm. My idle used to be 650 and I had issues there with it stalling. Raised it to 750 and adjusted on the idle torque tables and havent had any issues since. Except for this odd idle in gear.

Does your idle change in gear?

I've noticed at idle and in gear my zero pedal engine torque goes up, TM advanced comes up and timing advance will lower some.

Tune the airflow models, you are fighting torque calculations, it will never idle correct, until you properly tune it. The vve tables absolutely positively have to be properly calibrated or this thing wont idle correctly. What you are experiencing is the computer dumping timing because the torque is off. Torque is calculated directly from the vve table

I am not a very experienced tuner and I have a lot of questions, but from what it looks like to me your lope sound you are after is going away in gear because the idle speed is increasing. My TSP Stage 1/2 cam in my LT1 will do the same thing, once you get above a certain idle RPM you can't hear the lope anymore.

I have been fighting with mine endlessly trying to get the bucking while in gear at idle and reverse. I know it is caused by the controller going back and forth with timing trying to control the idle speed or torque or whichever it controls. I wish the bi directional tools worked in the scanner and I could manually control idle speed, spark, and AFR that way I could experiment with things.

Its like a chicken and the egg problem, does the ECM target a idle speed? or is there a missing table that defines idle target torque? so is the torque calculated from the virtual torque equation first, then the ECM puts out a spark value but how does it know which spark value to put out, does it use airflow first or torque? These are all unanswered questions and I am not sure anyone even really knows the truth besides the OEM's who program the things and even they are looking at something completely different than what we see in HP Tuners.

Anyway my next experimenting will be trying to richen it up and idle and see if the rpms and timing get more stable and settle out and it quits the bucking and surging. I can see that most of my misfires are happening at idle, which apparently is to be expected with a somewhat larger cam with that much overlap, but I think with some more fuel and probably timing I can cut down the misfires and I am also hoping by decreasing the misfires it will make the cats work better to burn off the unburnt fuel smell at idle which I hate.

There are no missing tables, everything is there. These are entirely different animals than the gen 3 and 4 stuff. If the airflow models are not correct to within a couple of percent, than you will end up with a very bad idle, horrible shifting, stalling when stopping, and all kinds of other junk

ALSO A NOTE OF THE BI-DIRECTIONAL CONTROLS. i THOUGHT THEY DIDNT WORK RIGHT WHEN I STARTED MESSING WITH THESE THINGS BACK IN 13', HOWEVER, ONCE I GOT THEM PROPERLY TUNED, THE CONTROLS WORK. THE PCM WILL NOT ALLOW BIDIRECTIONAL CONTROL WHEN ITS CONSTANTLY IN TORQUE MANAGEMENT, WHICH IS WHATS HAPPENING WHEN ITS FIGHTING IDLE

I have spent a long time trying to adjust VVE and MAF (even though I think MAF is calibrated from the factory and it seems to me when you change it you lose the correlation between MAF Hz reading and an actual amount of airflow)

I got to the point the more I adjusted the worse it got and the only filtering I was using was filtering out cells below about 150 counts. I tried to make better filters to try to filter out only the steady state response of the wideband but I couldn't get anything to work. Is there a special VE table that it references for idle? I know there is one for cranking or does it just reference the main virtual one?

My theory is that with the bigger cam and overlap the stock narrowbands are no longer working correctly (I had to increase proportional gain and decrease integral delay on the O2 feedback loop to get a delayed response code to go away) and the narrowbands are incorrectly adding to much fuel? I know most people that add cams don't care about the cats and probably delete them anyway I just wish I could get it working like stock or at least close to it.

Thanks for the help

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Originally Posted by cmitchell17

I am not a very experienced tuner and I have a lot of questions, but from what it looks like to me your lope sound you are after is going away in gear because the idle speed is increasing. My TSP Stage 1/2 cam in my LT1 will do the same thing, once you get above a certain idle RPM you can't hear the lope anymore.

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yeah you are right. i think i was just chasing something that wasnt there. it idles perfect just smooths out in gear. checked vve and maf and both were within 2%. i still need to get a stall converter ordered. ill probably do that monday. thanks for the help guys.

Do you still have cats? If so is the exhaust smell like stock? My TSP Stage 1/2 228/236 114-LSA smells bad at idle. It basically smells the same as if I had removed both cats completely. I had to adjust the O2 closed loop feedback proportional gain and integral delay some to keep it from throwing a delayed response code, but it does keep towing codes for catalyst inefficiency. So I'm not sure if maybe the overlap is throwing off the O2 sensors and making it run rich enough to where the cats can't clean up the extra unburnt fuel (which is not likely since my wideband is reading .97-1.03 lambda reading), or it is misfiring too much at idle leading to too much unburnt fuel and the cats can't clean it up. I am just curious if yours is doing that since I can't find anything else online of where people have complained about it in cammed engines, although most people don't care about the cats or they have removed them.

My 218/226 with a 32% over fuel lobe smells alittle rich at idol with stock cats. I don?t have a wideband installed yet though. I?m getting headers next month with a catless y pipe. So I?m just waiting for that to install my wideband and re- work the tune. It runs good for now so I?m trying to fight the urge to mess with it. I had a someone remote tune it since I needed it up and running since it?s a DD. I didn?t have time to learn how to tune this new platform. Now I?ve had time to play with it more.

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Originally Posted by cmitchell17

Do you still have cats? If so is the exhaust smell like stock? My TSP Stage 1/2 228/236 114-LSA smells bad at idle. It basically smells the same as if I had removed both cats completely. I had to adjust the O2 closed loop feedback proportional gain and integral delay some to keep it from throwing a delayed response code, but it does keep towing codes for catalyst inefficiency. So I'm not sure if maybe the overlap is throwing off the O2 sensors and making it run rich enough to where the cats can't clean up the extra unburnt fuel (which is not likely since my wideband is reading .97-1.03 lambda reading), or it is misfiring too much at idle leading to too much unburnt fuel and the cats can't clean it up. I am just curious if yours is doing that since I can't find anything else online of where people have complained about it in cammed engines, although most people don't care about the cats or they have removed them.

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No I have the catless Y. Sometimes I wish i did.

Do you have the mini cats? I've heard some say they clean up the smell for them and then some say they still smell fuel and have O2 and cat codes.

I still have both stock cats and completely stock headers and exhaust system. I hope the issue is maybe timing is just getting too low at idle because I can't figure out the idle torque settings and tuning, and since the timing is so low its making it misfire more and that is leading to more unburnt fuel that the cats just can't burn off in time.

It could just be something you have to deal with when you put a cam in, I just don't know since everyone gets rid of cats.

I am going to put my wideband back in as mbray suggested and try to get VVE and MAF closer, I think I need a better way of filtering the correction data to try to only give me steady state values instead of transient wideband feedback that is throwing things off.

I tried to hook up my VXdiag Chinese MDI GDS tool to try and manually control timing but it keep having communication problems.

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Originally Posted by cmitchell17

I still have both stock cats and completely stock headers and exhaust system. I hope the issue is maybe timing is just getting too low at idle because I can't figure out the idle torque settings and tuning, and since the timing is so low its making it misfire more and that is leading to more unburnt fuel that the cats just can't burn off in time.

It could just be something you have to deal with when you put a cam in, I just don't know since everyone gets rid of cats.

I am going to put my wideband back in as mbray suggested and try to get VVE and MAF closer, I think I need a better way of filtering the correction data to try to only give me steady state values instead of transient wideband feedback that is throwing things off.

I tried to hook up my VXdiag Chinese MDI GDS tool to try and manually control timing but it keep having communication problems.

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Your wideband bung is in before the cats right? If you are getting close to stoich before the cat then you shouldnt be smelling anything if you have the stock cats. Are your fuel trims off?

Long term trims are usually in the 3-5% range, sometimes a few cells get out in the 10% range, and then randomly sometimes you will see a short term trim go out to like 23% just for a second.

So I ended up removing the stock narrowband #2 sensor after the primary cat and putting my stock narrowband #1 in its place, then I put my wideband back in the bung right after the header collector merge. I am still trying to get someone to weld in an extra bung for me, but I am curious to see how this setup works out, so far if I remember correctly I think it already threw a code for the O2 feedback so the stock narrowband may not work after the cat.

So according to my wideband I am pretty close to stoich at idle (.95-1 lambda readings), but whats interesting is looking at the wideband feedback compared to the stock narrowband switching frequency. Keep in mind the bank 2 narrowband I moved after the cat in the second O2 sensor location (the one that just monitors catalyst efficency) and the wideband is now in its place. However it looks like the switching may be out of phase and when the bank indicates lean it is rich. I am assuming the bank 2 sensor is switching at a lower frequency as compared to the bank 1 because I moved it after the cat maybe? I realize this is not the way to do it, I just don't have a choice until I can find someone to put in a bung for me, or maybe just go ahead and buy headers with an extra bung in them.
Attachment 97065

And I got your message SILV thanks a lot, here is my tune file.
Attachment 97066

So I apologize for doubting you. I kept thinking there is no way my VVE could be off that much since just looking at my wideband gage at idle I am seeing .97-1.03. I decided to put my wideband back in and my VVE table kept getting thrown off in other cells when I was trying to calculate the coefficients. So I decided to try and balance out the zones by adjusting the rpm and p ratio zone boundaries. After I did that it recalculated the table and I decided to smooth it out and then just decided to just use that as a new baseline and go out and log.

I started the car from a cold start and immediately the idle was almost like stock, no more bucking with the timing rapidly fluctuating. So somehow I must have just by chance gotten the idle cells right on. However it started to warm up and change idle speed and it started doing it again. So I have faith now that that is the problem I just need better filtering techniques and figure out how to calculate the coefficients without it throwing off other cells.

I still have a problem that makes no sense to me.

Here is my VVE histogram and I circled my idle region:
Attachment 97085

So you can see I am almost right on and like you said this is what made my idle good and corrected my airflow so the idle control wasn't throwing itself off.

However you can see in some of the lower p ratio and a little higher rpms cells it is requiring major correct above 10%. I also have a 150+ count filter enabled along with ensuring it is at steady state timing above 15 degrees and also zero speed and zero accelerator so I know these values are not just bad transient data:
Attachment 97087

But when you look at my VVE table there is no way it would be this discontinuous:
Attachment 97088

If everything is correct here I would need to apply a 14% positive increase to the VVE table where I circled and to me this just doesn't look right, I would be increasing VVE as p ratio goes down which absolutely doesn't make sense:
Attachment 97089

What am I missing here?

Quote:

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Originally Posted by cmitchell17

Long term trims are usually in the 3-5% range, sometimes a few cells get out in the 10% range, and then randomly sometimes you will see a short term trim go out to like 23% just for a second.

So I ended up removing the stock narrowband #2 sensor after the primary cat and putting my stock narrowband #1 in its place, then I put my wideband back in the bung right after the header collector merge. I am still trying to get someone to weld in an extra bung for me, but I am curious to see how this setup works out, so far if I remember correctly I think it already threw a code for the O2 feedback so the stock narrowband may not work after the cat.

So according to my wideband I am pretty close to stoich at idle (.95-1 lambda readings), but whats interesting is looking at the wideband feedback compared to the stock narrowband switching frequency. Keep in mind the bank 2 narrowband I moved after the cat in the second O2 sensor location (the one that just monitors catalyst efficency) and the wideband is now in its place. However it looks like the switching may be out of phase and when the bank indicates lean it is rich. I am assuming the bank 2 sensor is switching at a lower frequency as compared to the bank 1 because I moved it after the cat maybe? I realize this is not the way to do it, I just don't have a choice until I can find someone to put in a bung for me, or maybe just go ahead and buy headers with an extra bung in them.
Attachment 97065

And I got your message SILV thanks a lot, here is my tune file.
Attachment 97066

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I don?t know about being rich when it?s really lean.

To me that O2 mv and wideband are hand in hand so to say.