Newbi questions on tuning LQ4

[jemarshall64]

So I got a laptop and gave another run at the RAF using the desired air flow last night. After I did it, I noticed that the original tune was not set up for a 90mm TB. Today I adjusted hat number and re-did the RAF run. While messing with that and then re-setting the IAC, I came to realize that the idle was not following what it should. Looking into it, I figured out that the thing thinks its always in gear and will only go off the in gear idle speed target. The only reason I can think it would do this is because it does not have the black gear selector box on the side of the transmission. From what I can remember without pulling the seat and floorboard out of it is that the harness does not have the pig tail for it either.

So will this really have an effect on it? It is an off-road vehicle only anyways.

On the topic of it being off road only, I would like to set it up so that the TCC is always locked. With it being a 4L80 it cant lock in first which is fine for crawling, and then 2nd and up it would lock up and stay there. Does anyone have any pointers to do this. I have looked into it a little bit, but did not have the editor with me so I couldn't follow along and need to go back and find what I did find.

With doing the RAF by measuring desired air flow, do I need to do it multiple time, or is once through fine? I would imagine going back to the LTIT might dial it in some more, but if its just fine adjustments, it would be something I could take more time to deal with latter.

[jemarshall64]

I am still fighting the hanging idle issue on start up. It only does it when starting it, not when you let off the throttle. I cant seem to find anything about this. When it fires off it comes back down to just over 1000 RPM's and then hangs out there for almost 15 seconds before it will start coming down to an idle. Blip the throttle and it drops right back to idle within 3 seconds. This is driving me nuts. Anyone have any insight in how to fix this?

Attached my current tune setup and a quick log showing what its doing.

[5FDP]

Looks like you are fighting a lean problem too, your wideband is going way lean after a little bit.

Once it does come down after you blip the throttle, the short term trims are trying like crazy to add fuel back in.

[cobaltssoverbooster]

i see your desired idle airflow is requesting roughly 7 g/s at 750rpm but your raf table is set to 10.45 g/s.
lower your iac reset postion to say 160 so when you start it the IAC isn't hanging open an unnecessary amount.

I do see the lean event just after startup and im curious if its because your p/n raf is way off. On startup the ecu uses the programmed values and then as it runs and gets time under learn modes then it settles itself out over time. revving the engine forces the ecu to skip warmup procedures and go right to close loop mode. This was a trick i would do in the Cobalts that had high rpm idle warmup still disabled and i didnt want to wait for it to finish before i scanned for particular things.
In a manual transmission set p/n is the only Raf that is filled in because a manual in gear is driving and thus no longer running in the idle tables.
In your auto transmission the freewheel effect in p/n will require a lower airflow than when its in gear and on the converter.
RAF1.jpg

[jemarshall64]

Looking at the chart, the IAC is at right about 150 for the time that it is hanging, and then coming down to control the idle. My guess is that the IAC reset is where the IAC desired number starts counting down from, and it doesn't move until that number gets to the 150, and then it will drive the IAC closed? So I dropped it to 150 which is where the desired IAC was at, will give it a try tonight.

So when I was measuring the RAF last night, I noticed that the only desired idle setting that would make any changes to the engine is the In Gear section of the table. The P/N side never takes control of it, even though it is in Park. I think it might have to do with the rig not having the black gear indicator assembly on the trans. I am not sure whats going on there. I know it knows what gear its in without it for shifting, but the P/N side looks to be effected. I was thinking that since it thinks the rig is in gear that the values I got should be in the In gear section of the air flow tables, even though it is not really in gear. Following the procedure it also says to copy the values into both gear and in park tables, and then redo the procedure for in gear and just update that side of the table. The reason I noticed that the Gear side of the desired Idle speed was the side controlling it, was from where the procedure tells you to drop the in gear side idle down 100 rpms under the P/N side. The numbers you see in the RAF table are the numbers I got last night doing the Idle procedure, but using the Idle desired air flow instead of the LTIT like you had suggested. The log showing the hanging idle is one I did after I did the RAF, so it was already up to engine temp.

When I did the log, I made sure to start it up and wait for it to come to idle before tapping the throttle. I then shut it off and restarted it to show that even on a re-start it would do it. Since it was already warmed up, I did not think the PCM would make it do any warm up procedures. I was also wanting to see/show that it is only doing it on startup and not when you let off of the throttle.

It also doesn't make since to me that if I had the 10.45 g/s in the table, why was it asking for the 6.64 g/s. Shouldn't it be asking for what the idle air table has in it?

In the procedure it says to do the RAF 2 times for each scenario, do you have to do that when you use the desired air flow, or will only 1 time be enough?

[cobaltssoverbooster]

Looking at the chart, the IAC is at right about 150 for the time that it is hanging, and then coming down to control the idle. My guess is that the IAC reset is where the IAC desired number starts counting down from, and it doesn't move until that number gets to the 150, and then it will drive the IAC closed? So I dropped it to 150 which is where the desired IAC was at, will give it a try tonight.

So when I was measuring the RAF last night, I noticed that the only desired idle setting that would make any changes to the engine is the In Gear section of the table. The P/N side never takes control of it, even though it is in Park. I think it might have to do with the rig not having the black gear indicator assembly on the trans. I am not sure whats going on there. I know it knows what gear its in without it for shifting, but the P/N side looks to be effected. I was thinking that since it thinks the rig is in gear that the values I got should be in the In gear section of the air flow tables, even though it is not really in gear. Following the procedure it also says to copy the values into both gear and in park tables, and then redo the procedure for in gear and just update that side of the table. The reason I noticed that the Gear side of the desired Idle speed was the side controlling it, was from where the procedure tells you to drop the in gear side idle down 100 rpms under the P/N side. The numbers you see in the RAF table are the numbers I got last night doing the Idle procedure, but using the Idle desired air flow instead of the LTIT like you had suggested. The log showing the hanging idle is one I did after I did the RAF, so it was already up to engine temp.

When I did the log, I made sure to start it up and wait for it to come to idle before tapping the throttle. I then shut it off and restarted it to show that even on a re-start it would do it. Since it was already warmed up, I did not think the PCM would make it do any warm up procedures. I was also wanting to see/show that it is only doing it on startup and not when you let off of the throttle.

It also doesn't make since to me that if I had the 10.45 g/s in the table, why was it asking for the 6.64 g/s. Shouldn't it be asking for what the idle air table has in it?

In the procedure it says to do the RAF 2 times for each scenario, do you have to do that when you use the desired air flow, or will only 1 time be enough?

if your not going to tell the ecu the gear by not running the prndl switch then your going to have a hard time dialing in the idle airflow because the ecu is going to be constantly trying to learn from one desired airflow to another.
the cam doesnt need as much air to stay running in p/n as it does in gear. Desired Airflow the ecu's calculation based on what it has to adapt to to keep the engine at the listed rpm. I just finished a .580" lift 235 duration 112 cam for a coworker and i have 11.5 g/s in gear and 6.7 g/s p/n.
The RAF is a starting point, the idle airflow adapt tables shift the raf internally to hold the idle and based off of the adaption movements the ecu can calculate the desired airflow.

the lower the stall on a converter with a cam, the more you will struggle to tune the idle without a prndl connection.

you still do the raf read twice in each scenario because the first one may be off so far that the adaption can be at its limits. the second one is there to basically finalize the data with a more refined range of adaption.
in your case its pointless to do the second scenario because you dont have the wiring to tell the ecu to switch tables. basically your ecu is acting as if there was a manual transmission attached.

[cobaltssoverbooster]

if you had to fudge it because there is no way to add a signal for prndl then i would do a p/n read and externally record the values registered. then i would do an in gear read and record them externally. subtract the p/n from the in gear results and divide by 2. this gives you the half way value which would limit the amount of adaption factor that would have to be applied in either scenario.

[jemarshall64]

The harness I am running is a PSI HAR-1092. From what I can remember it does not have the connector for the PRNDL switch. By the time I realized what was going on the motor was to hot for me to stick my head in next to it to look down the tunnel and see if there was or wasn't actually a connector for it. I am pretty sure there isn't. I will try and check before I start it tonight.

The converter is a stock 99 Silverado converter so it is pretty low. It was in the plan to replace with a higher one when the trans goes to hell and needs rebuilt.

I could possibly hook up a P/N switch to the shifter somehow, would have to look into that. I don't care about it keeping the rig from starting, but would be able to signal the PCM for the tables. I will have to see on that. I am running an Art-carr unit and I am pretty sure there has to be some setup for it to do P/N. I will do the RAF in drive tonight and see what I get for numbers on it and then do the math.

I am also thinking I have made enough little changes to it too that I need to go back and redo the VE tables. I was not 100% happy with them as it was, piecing things together as I go and can think about how it went and realize that it wasn't just right. There was allot of little setting that were off that I have changed that I think are not doing the base tables any good. It's all a learning experience. I will try to do some logging this weekend, but its not really going to be the type of driving that would be good for it though. If not I am thinking I will take it out one day next week and do some more tuning on it. I need to get the old man out and take him for a ride anyways.

Thank you very much for your inputs.

[jemarshall64]

So I just finished the in gear idle. The cells I am working with are 68 to 241 right now. The air flows came out all lower except for 68 and 241 deg. I will do another run with it in park in the morning and do the math like you suggested. I should be able to get another neutral test in the morning, and another in drive test in the evening.

The plug for the PRNDL switch is not part of the harness. They do offer a switch for the shifter for a park safety switch. I am thinking of just sitting down and figuring out how to make it think its in park just to do the tuning for now, and then worry about getting the switch latter. I just need to know where I need, or don't need voltage when it's in park.

Its still doing the thing where it runs lean till 160 deg and then drops into the correct F/A mix.

[jemarshall64]

Here is what I found.

https://ls1tech.com/forums/conversio...onversion.html

Long story short, change the PCM to P/N only, which it was set for PRNDL, and ground out pin B #34. This will make it think its in P or N. Looking at the switch for the shifter they make, I think I can make one up with a chepo limit switch much easier. Thinking that will be a nice night shift project at work.

[jemarshall64]

The wire for Pin #34 was already in the harness. It was part of the under dash section I only used the brake switch wire from. I was able to just ground it out and run the RAF again. After I got the numbers I updated the running tune I have and started it and the hanging issue is better. Not completely gone though. I am thinking that since it thinks its in gear and the higher air flows it is fighting itself. I will try and get another RAF done this afternoon before I head out, and maybe another one when I first fire it tomorrow morning. It is doing much better all around, your inputs have been a huge help.

[5FDP]

Not to throw more sticks in the fire but only at a quick glance of the logs I think your passenger side o2 sensor is dead, it's drops out to 50mv and just stays there.

[jemarshall64]

Looking at the logs, it started running low on the RAF run on the 26th. It will still move up. I am not sure if it is an O2 sensor or a fuel issue.

[jemarshall64]

Scratch that, that is as far back as I can see when I was logging them. I will have to verify which side it actually is just for S&G. I'll go pick up one and swap it in. Kind of irritating, these are essentially brand new......

[jemarshall64]

I don't think it is an O2 sensor. Before and after logs of swapping it out..... any ideas what would be causing it to jump around like it is?

[5FDP]

I don't know what to say anymore I guess, just so much seems wrong and that OS is pretty weird compared to a lot of "boosted" OS's go. A normal 1 bar OS would have far less tables and be easier to navigate.

Your o2 sensors drop out, short terms trims are going crazy, your wideband shows this thing running extremely lean all the time. I see 16-18 AFR most of the time and the trims are pushing 30-50% to get fuel back in.

Closed loop is still disable thoughout all this. I feel if you disabled open loop fuel corrections with the STFT it would be lean 90% of the time until the VE and MAF were 100% dialed. Not being able to get long logs on an fairly aggressive motor setup is very hard to tune.

[jemarshall64]

I am going to defiantly go back into tuning the 'VE and MAF. Hopefully I can get it out for a day of just tuning this next week. The last logs I was getting were in the 45 to 60 min range. Do I need to stretch them out any further?

The passenger O2 being so erratic I don't get, I am thinking it might be a fuel injector. Is it possible to pull the plug off of 1 injector at a time and see if the erratic behavior goes away, or will doing that cause other issues?

I am very thankful for your help. Like I have heard, it's an adventure, not an experience, and I am just starting. I think part of my issues is I feel rushed to get it done. I need to just slow down and start over at the beginning and take some more time. There have been some other changes I have made since doing the little bit of 'VE table work that I think is impacting it also. After this trip tomorrow I'll throw a set of plugs, fuel filter and clean the air filter, load the old man up and go spend a day running around the woods.

[jemarshall64]

Standing here doing a RAT run and there are a few odd things. First is I am wondering if the driver O2 isn't the one having issues.

The WB is in the passenger side. The WB on the log is very erratic, while the gauge is pretty steady, and they do not read the same......

After it got to 230 set engine temp, the passengers side one started bouncing like the passenger side one started coming up and bouncing around.

[jemarshall64]

So I figured out the O2 sensor issue, it turned out to be injector plugs that had ATF on them. My doubler vent is on the firewall and when the trans had gotten hot it puked some ATF out and soaked the last two injectors on the passenger side. I cleaned them up with some spray and it settled it right out. Of course I now have a brand new spare O2, but that's not necessarily a bad thing.

It ran great on the trip this last Saturday. Never really pushed it too hard, but I was never really in a position to run and logs on it.

Took it out Monday and put the 15 year old behind the wheel so he could get some steering stick time and ran logs with him driving. This ws his first real time driving so he was pretty timid driving which I think really helped. I tend to want to put my foot in it all the time. . I got a couple logs on the VE tables and I think they are doing really good. I only did one run for MAF tuning though. Looking at the guide I am using, I am not 100% sure which thing I should be logging/using to correct the MAF tables.

I am using the guide put together by CPIG.

On page 16 under dialing the MAF the way it reads I should have my graph set up to do AFR Error [Math] Percentage, instead of LTFT+STFT [Math]. There is a huge difference in the numbers it comes up with between these two different ways, the afr error way wants allot more air it seems. Which one should I be using? Or should I do the AFR error, and then dial it in with the LTFT+STFT?

By using the AFR error it seems to have an issue where it will go really lean when I left off the throttle and am coasting, but I am not sure if that is related to the MAF tuning or not.

When I got home and fired it off to unload it it went very lean at an idle and did not want to come back down on the running tune. I let it cool down and fired it off to log what it was doing and it I could not get it to do it again .

I still have the data from both of the ways to scan the MAF tuning so I can put it in either way, I just need to know which way is correct. Without knowing which one I should use I did not spend anymore time on it. We have also had very high temps the rest of the week and they shut down the woods on us so I cant get it back out right now.

For other issues it still has from before, there is how fast it idles down when starting it up hot. It is coming down to idle faster than it was, but still not as fast as I think it should. I am not sure what to do here, but with more tuning I think it might get better.

The other issue is the running lean on a cold start until it gets to 158-160 deg engine temp. This is driving me nuts and I can not find what is doing it. The AFR command is really rich and it sits there high, once it hits that temp it settles out, the AFR drops down, the IAC dials back, and the timing settles out and it idles beautiful. I just cant find anything that would do this.....

I have attached a log of the last VE run, the MAF run and a log from tonight before I left for work showing what its doing on the lean start up. I also attached my running tune that is currently installed.

[jemarshall64]

So I think I found the lean on idle, but now I believe I have to redo the RAF. The OL EQ Ratio was set to 1 across the board. I played with it a little today and it made a huge difference. Setting it to a stock table was so rich it wouldn't even run. I found one where it seems happy and will idle somewhat.