Just started tuning- have a stalling issue I need help identifying

[Namreje]

I recently swapped my 84 C10 with an '03 LQ4 w/ SS2 Cam, PAC 1218 springs. It is DBW. I have an Ebay 4" intake, Summit cast manifolds, dual 2.5" exhaust with X pipe and 4l80E with a factory 2200-2400 torque converter (temp until spring). I also installed an AEM wideband for MAF and SD tuning and am using the EGR sensor inputs on the PCM.

Up until this week, I've been slowly working on getting the MAF dialed in with no issues. Things were going pretty well I thought so I decided to look into cleaning up idle and making some timing changes knowing that I would still need to go back and correct MAF. I changed my RAF and adjusted timing based on Youtube videos I had watched and going through forum posts. I don't know if I'm on the right track or not, but I'm trying to learn as I go so I may be way off.

The issues I'm having are that the truck has stalled on me each of the last 3 days on my way to work. Coincidentally enough, it's been in the exact same spot each time (conveniently in the Dunkin Donuts parking lot) about a mile from my house. It starts up and idles fine until that point. I am able to re-start the truck and from there don't have any other issues on my ~10 minute or so ride to work. The other issue I have is from a stop (at an intersection) I am having some serious stumbling issues also. It seems like the longer I am at a stop, the more likely I am going to have that issue.

I have gone in and changed some other settings based on what I am finding online, but have largely reverted back to the initial tune plus the setup for MAF tuning as well as RAF, Timing and Idle speed.


Attached is the log from a short drive I did tonight where the truck both stalled and then later stumbled in an intersection. I can post other logs if needed, but with the little changes I have made, this one is the most applicable. Thanks in advance for your help!

[dhoagland]

From what I understand you should not worry about idle until you have your airflow dialed... How are you getting your AFR error? The feed back from your WB is voltage in your log (maybe thats the way it is, I've never transformed one through the ERG circuit)...

You say DBW
Is that how the ECM was originally configured?
Are you using the Petal and TAC that was from the same doner vehicle? I know mis match between petals and OS's can be problematic..

[Namreje]

Yeah, I've read to wait and do idle after airflow. Some say MAF first, others say VE and I even saw something that said Idle should be first. From what I read/watched, I knew messing with RAF and timing would cause me a little grief because I wasn't quite dialed in with MAF yet. The first time the truck stalled this week, I only had done the MAF setup. I did the timing and RAF to try and counteract that the same afternoon and was very happy with how the truck was running... until it stalled again the next morning.

Coincidentally enough, today I drove a different route and the truck did not stall. I didn't compare the two logs to see what differences, if any, exist.

I am getting AFR error with user math set up in VCM scanner. I took a screenshot of the expression and attached it for reference.

The ECM was originally configured for DBW and I have the original TAC module and pedal that came with the motor from the same donor.

[Hondaeater]

Yeah, I've read to wait and do idle after airflow. Some say MAF first, others say VE and I even saw something that said Idle should be first. From what I read/watched, I knew messing with RAF and timing would cause me a little grief because I wasn't quite dialed in with MAF yet. The first time the truck stalled this week, I only had done the MAF setup. I did the timing and RAF to try and counteract that the same afternoon and was very happy with how the truck was running... until it stalled again the next morning.

Coincidentally enough, today I drove a different route and the truck did not stall. I didn't compare the two logs to see what differences, if any, exist.

I am getting AFR error with user math set up in VCM scanner. I took a screenshot of the expression and attached it for reference.

The ECM was originally configured for DBW and I have the original TAC module and pedal that came with the motor from the same donor.

Hello, would you try log using these channels? Did you get different injectors than what was on the 6.0L? You do not finalize the idle until the MAF and VE but you can confirm a lot of errors that effect all the other tables from idle logs. It is the baseline. Enable closed loop and LTFT on one idle log if you would to confirm the AEM is not skewed. You can switch OL ON in the Special functions of scanner so you would not need to re-upload tune each time and can be one log. Both fuel models too helps. You can do this MAF only as it is but again establishing a baseline.
Looking forward to it.

[Namreje]

Hey Hondaeater, I am using the original injectors that came with the motor. I downloaded your channels and will go out and get an idle tune. I assume I would need to let it cool before getting another one with closed loop enabled and LTFT on? If so, I will try to get another later today or tomorrow. What do you mean by both fuel models? Thanks for your help!


added log file and updated tune from the other day. I had decreased RAF in gear.

[Hondaeater]

Hey Hondaeater, I am using the original injectors that came with the motor. I downloaded your channels and will go out and get an idle tune. I assume I would need to let it cool before getting another one with closed loop enabled and LTFT on? If so, I will try to get another later today or tomorrow. What do you mean by both fuel models? Thanks for your help!


added log file and updated tune from the other day. I had decreased RAF in gear.

SS2 cam without cam card I am not sure if idle can be lowered but the airflow IS off and startup air comes out too fast. Idle spark is a little high but again it depends on what it wants. A little goes a long way here. In this R1 file I enabled both fuel models MAF and VE. You were in OL MAF only mode. I know you said MAF was pretty well dialed in but there is some smoothing needed. Lets see how close it will run in CL to the OL and fine tune adjustments ok?
My Channels do not include your WB o2 from EGR. Again, lets see how it is doing baseline in CL and please add your EGR- WB channel to logs. I re-enabled idle adaptive gear min/max too.
When it stalls is it when slowing to a stop or while stopped in gear like waiting to pull up in the drive-thru line or at a stop sign? CL will tell more.
Driving log with these channels. If able to do a closed loop idle fine but its ok. Drive in CL and idling in gear stopped for a few seconds trying to recreate your issue. Add EQ ratio to channels too. It is getting crowded you should only use 25-28 channels for Gen3 but we can narrow them as we deal with issues.
Compare the tune files before using.

[Namreje]

SS2 cam without cam card I am not sure if idle can be lowered but the airflow IS off and startup air comes out too fast. Idle spark is a little high but again it depends on what it wants. A little goes a long way here. In this R1 file I enabled both fuel models MAF and VE. You were in OL MAF only mode. I know you said MAF was pretty well dialed in but there is some smoothing needed. Lets see how close it will run in CL to the OL and fine tune adjustments ok?
My Channels do not include your WB o2 from EGR. Again, lets see how it is doing baseline in CL and please add your EGR- WB channel to logs. I re-enabled idle adaptive gear min/max too.
When it stalls is it when slowing to a stop or while stopped in gear like waiting to pull up in the drive-thru line or at a stop sign? CL will tell more.
Driving log with these channels. If able to do a closed loop idle fine but its ok. Drive in CL and idling in gear stopped for a few seconds trying to recreate your issue. Add EQ ratio to channels too. It is getting crowded you should only use 25-28 channels for Gen3 but we can narrow them as we deal with issues.
Compare the tune files before using.

Added a picture of the cam card so that you can see the details there. I will add the EGR-WB and EQ ratio channels to scanner also.

When it stalls, it is typically when I am slowing to a stop. I get a hesitation more at a stop, but not all the time.

I'll load up that tune and set up the scanner to get a driving tune with the info you are looking for. Thank you again!

[Hondaeater]

cool. yes that is a nice cam and very LS friendly. When you said 4" intake did you modify the MAF sensor housing? Added a little to Throttle cracker. Try R1 firtst then R2 for effect. The R1 having the adaptive back in may be enough.

[thebrickbandit]

i have a good tune for my 2010 charger srt8 5 spd.... 93 oct....cai....180 tstat. catback lmk if interested

[Namreje]

@hondaeater

I was able to go for a long ride tonight to get some data logged using this tune.

There was some stumbling at one point (around 7:26pm in the log) when I was entering a traffic circle. It really bogged down and then seemed to recover after a few seconds. I did notice that it seemed like at several stops (red lights, waiting for traffic, etc) the rpms dipped and then surged. Not sure if that is the correct term or not, but the RPMs seemed to increase to about 1k-1,100k randomly.

Other than that, everything went pretty well, right up until I stopped at the gas station after driving for about an hour. As soon as I pulled up to the pump and just about came to a stop, the truck shut off. I ended the log there and then filled the tank. When I was done, I tried starting the truck and it would start, but die almost instantly. It did this several times until I feathered the throttle and seemed to get it stable enough to drive home (about a mile). When I got home, I backed into the drive way and once I came to a stop, the truck shut off again. I put it in park, started it again and it seemed to struggle, but didn't shut off again. I turned it off at that point. I'll include that short log file also so that you can review that.

No I did not alter the MAF housing. I removed the original intake tubing and added it to the ebay intake using hose clamps and silicone boots/sleeves right after the filter.

Not sure if I added EQ Ratio correct or not, but it is in channels. I really appreciate you taking the time to help me work through this. I look forward to hearing your thoughts on this!

[Hondaeater]

@hondaeater

I was able to go for a long ride tonight to get some data logged using this tune.

There was some stumbling at one point (around 7:26pm in the log) when I was entering a traffic circle. It really bogged down and then seemed to recover after a few seconds. I did notice that it seemed like at several stops (red lights, waiting for traffic, etc) the rpms dipped and then surged. Not sure if that is the correct term or not, but the RPMs seemed to increase to about 1k-1,100k randomly.

Other than that, everything went pretty well, right up until I stopped at the gas station after driving for about an hour. As soon as I pulled up to the pump and just about came to a stop, the truck shut off. I ended the log there and then filled the tank. When I was done, I tried starting the truck and it would start, but die almost instantly. It did this several times until I feathered the throttle and seemed to get it stable enough to drive home (about a mile). When I got home, I backed into the drive way and once I came to a stop, the truck shut off again. I put it in park, started it again and it seemed to struggle, but didn't shut off again. I turned it off at that point. I'll include that short log file also so that you can review that.

No I did not alter the MAF housing. I removed the original intake tubing and added it to the ebay intake using hose clamps and silicone boots/sleeves right after the filter.

Not sure if I added EQ Ratio correct or not, but it is in channels. I really appreciate you taking the time to help me work through this. I look forward to hearing your thoughts on this!

The VE table is where most of the fuel is biased from below 4000. I know you had been working on MAF and VE was not adjusted yet. Could do the MAF only in CL to check your OL. Thats the point. If in OL you will be putting it into CL for driving anyway and your mods are not major so it is very appropriate to work in CL. I made some changes to the VE. Would you idle in CL with idle channels? The OL is all I had. Also in Gear idle in CL. Look at the idle desired, idle base (BRA table) and the MAF frequency Mass Airflow lb/hr. Your MAF was calling for 87ish lb/hr the table called for 62ish at temp in scan and it desired 54. LTIT was removing -15-19lb/hr. Again this was OL and if you would idle in CL and put into gear at op temp to get needed setting of BRA in gear. Cold start is helpful but we are not trying to dial in the idle just make it stable to drive! and flesh out the VE and MAF. I would never want to put you in harms way so maybe using a parking lot until its more stable. That sounds harry in traffic and wanting to stall. Adaptives are to be nuetralized when finalizing the idle.

[Namreje]

The VE table is where most of the fuel is biased from below 4000. I know you had been working on MAF and VE was not adjusted yet. Could do the MAF only in CL to check your OL. Thats the point. If in OL you will be putting it into CL for driving anyway and your mods are not major so it is very appropriate to work in CL. I made some changes to the VE. Would you idle in CL with idle channels? The OL is all I had. Also in Gear idle in CL. Look at the idle desired, idle base (BRA table) and the MAF frequency Mass Airflow lb/hr. Your MAF was calling for 87ish lb/hr the table called for 62ish at temp in scan and it desired 54. LTIT was removing -15-19lb/hr. Again this was OL and if you would idle in CL and put into gear at op temp to get needed setting of BRA in gear. Cold start is helpful but we are not trying to dial in the idle just make it stable to drive! and flesh out the VE and MAF. I would never want to put you in harms way so maybe using a parking lot until its more stable. That sounds harry in traffic and wanting to stall. Adaptives are to be nuetralized when finalizing the idle.

I will get an idle log in park and another in gear, both in CL. I will try to get cold start, but will take what I can get. At a minimum I can wait until lunch break to log it. I wanted to be able to get an idle log from early in the am as temps are starting to dip, but I leave for work too early and the truck is too loud to let rumble the neighborhood. So, you want me to bring it up to temp and then put it into gear during the CL idle log in park?

I will check out the changes that you made in the tune as well. You mentioned earlier that my MAF table needed additional smoothing... is that something I should look at doing now or hold off? I saw conflicting info on how smooth it needed to be so I really tried to interpolate and smooth as little as possible to eliminate any larger spikes, bumps in the graph.

[Hondaeater]

I will get an idle log in park and another in gear, both in CL. I will try to get cold start, but will take what I can get. At a minimum I can wait until lunch break to log it. I wanted to be able to get an idle log from early in the am as temps are starting to dip, but I leave for work too early and the truck is too loud to let rumble the neighborhood. So, you want me to bring it up to temp and then put it into gear during the CL idle log in park?

I will check out the changes that you made in the tune as well. You mentioned earlier that my MAF table needed additional smoothing... is that something I should look at doing now or hold off? I saw conflicting info on how smooth it needed to be so I really tried to interpolate and smooth as little as possible to eliminate any larger spikes, bumps in the graph.

The file I sent was for the dual fuel mode in CL. If you are going to tune MAF, tune will need to be set up for MAF tuning just like the OL but using the CL and LTFT instead of disabling and using the WB. You have the concept down for how to adjust but that paste special % will make for a choppy airflow table. And if tuning the VE then fail the MAF sensor in CL and again look at the trend of % error and manually go in and adjust the table. Use interpolate to smooth the table. Abrupt changes will cause drivability issues. MAF has issues around 6000s and 8000s so MAF only CL very smooth throttle changes. If you are driving in traffic you are not getting good data. It needs to be as smooth as can be like on a service road or no traffic area.
I updated the Diagnostics channels to include the throttle follower and cracker airflow adders. Did you reduce the Cracker table because of a problem you were having? R2 has conservative cracker air added. R3 does not have adder but changes in Fuel tables.

[Namreje]

The file I sent was for the dual fuel mode in CL. If you are going to tune MAF, tune will need to be set up for MAF tuning just like the OL but using the CL and LTFT instead of disabling and using the WB. You have the concept down for how to adjust but that paste special % will make for a choppy airflow table. And if tuning the VE then fail the MAF sensor in CL and again look at the trend of % error and manually go in and adjust the table. Use interpolate to smooth the table. Abrupt changes will cause drivability issues. MAF has issues around 6000s and 8000s so MAF only CL very smooth throttle changes. If you are driving in traffic you are not getting good data. It needs to be as smooth as can be like on a service road or no traffic area.
I updated the Diagnostics channels to include the throttle follower and cracker airflow adders. Did you reduce the Cracker table because of a problem you were having? R2 has conservative cracker air added. R3 does not have adder but changes in Fuel tables.

I had reduced cracker before posting here based on info I had read. I thought I had put it back to original, but I must have missed that. I didn't see an R2. You had posted 1 and 3. Unless I missed it?

[Hondaeater]

lol, I made it but got side tracked. Try put cracker back in stock and IF IF it hangs while slowing down reduce it by half and again if still hangs 1/2 until you get the desired result. It usually happens in the lower speeds under 1600RPM and many times its the base airflow is off so every adder and adaptive table is off compounding the issue. Try to make sure the fuel tables are correct before going after Cracker.

It's like fuel injectors, if you have stock everything showroom car and put bigger injectors (but not insane big, 2x-3X bigger say) using Injector dynamics or FIC injectors with GM characterization data it shouldn't change any of VE or MAF tables and car runs just like stock.
You have really high idle spark P/N and in Gear and maybe try reducing to 20* instead of 26*. If the engine needs to add torque to stabilize the idle and you are maxed out then there is no headroom and adding spark does nothing from the over/under tables then it tries to use airflow which is much slower compared to spark and it can start oscillating. You could probably get by with 18*. I have a stage 3 .610 lift TSP cam in an LS swap that is idling happy at 700 P/N 675 in Gear and 20* idle spark.

[Namreje]

lol, I made it but got side tracked. Try put cracker back in stock and IF IF it hangs while slowing down reduce it by half and again if still hangs 1/2 until you get the desired result. It usually happens in the lower speeds under 1600RPM and many times its the base airflow is off so every adder and adaptive table is off compounding the issue. Try to make sure the fuel tables are correct before going after Cracker.

It's like fuel injectors, if you have stock everything showroom car and put bigger injectors (but not insane big, 2x-3X bigger say) using Injector dynamics or FIC injectors with GM characterization data it shouldn't change any of VE or MAF tables and car runs just like stock.
You have really high idle spark P/N and in Gear and maybe try reducing to 20* instead of 26*. If the engine needs to add torque to stabilize the idle and you are maxed out then there is no headroom and adding spark does nothing from the over/under tables then it tries to use airflow which is much slower compared to spark and it can start oscillating. You could probably get by with 18*. I have a stage 3 .610 lift TSP cam in an LS swap that is idling happy at 700 P/N 675 in Gear and 20* idle spark.

Ok, here is the idle log I just completed. I thought it was going to be in CL based on the tune, but it wasn't and I didn't catch it until a few minutes had passed. I did turn on CL though for the remainder of the tune. I also let it get up to about 225* and then shifted into drive with my foot on the brake for a few minutes so that you would be able to get the info for BRA.

Before I ran the tune, I did update it to return cracker back to stock and then reduced timing to 20* from 0-800 up to .28 g/s and then blended a couple of rows/columns each way up to 1600 and then copied from park to in gear. I want this thing to idle as low as possible for sure.

Let me know what you think.

[Hondaeater]

When you dropped the timing it was good but you should should lower the base idle too. 50rpm at a time. You can do this and adjust timing in scanner under the special functions to find the happy point. It is a balancing act lowering spark and airflow for any given rpm. You lowered the spark and that was good but it raised the airflow needed to take up the slack to maintain THAT rpm. If you watch the idle LTIT and STIT airflow you are trying to get those to 0, they went up big time beacause it's trying to keep it at that rpm. Since they are adding air, BRA will be ok and make adjustments in RPM until close to 0 adder and it may need more BRA.
Again we are not after the idle finalizing but to get it close enough so that when you are stopped or coming to a stop it is stable not stalling out, thats it! Then go after the VE and MAF. Revisit the idle if needed as you make fuel table adjustments but only after both models are adjusted. Remember spark has a big influence and its immediate. We want spark to control torque not the TPS adjusting for it. If you have unstable behavior investigate attack the spark first, that's usually the issue. Lower or raise the timing in the problem area by 4-5* and see if it corrects. Again it is hard to tell someone how to tune it's not overnight and I'm not a teacher. I know what works for me. This is the concepts not the instruction manual ok.

[Namreje]

Thanks for checking that out and helping guide me in the right direction. I will go in and mess around with VCM scanner later to fine tune spark and airflow. On a side note, bringing cracker back up to stock seemed to help. Further testing will confirm, but I think we're headed in the right direction. I completely understand about not being a teacher. I appreciate you taking the time to help explain it nonetheless!

Can you review the LTFT+STFT graph layout for accuracy?

[Hondaeater]

Thanks for checking that out and helping guide me in the right direction. I will go in and mess around with VCM scanner later to fine tune spark and airflow. On a side note, bringing cracker back up to stock seemed to help. Further testing will confirm, but I think we're headed in the right direction. I completely understand about not being a teacher. I appreciate you taking the time to help explain it nonetheless!

Can you review the LTFT+STFT graph layout for accuracy?

Glad to help. Looks fine if the frequency is correct from tune file. The decimal should have at least 1-2 place settings too. Are you using g/s or lb/hr? Doesn't matter but it may if you create histograms, better to be consistent.