Rough idle still and air flow

[lumberjacked]

I have an 07 Chevy Avalanche that I have had to replaced collapsed lifters on twice because of AFM. This second time around doing the work I deleted DOD and replaced the cam. The lift on the cam is exactly the same lift as before .500. I do not have a wideband installed and I wasn't planning on doing that because the intentions of the truck are more of a daily driver than something to play with. My goal is to just get it back to good running condition.

Ive already disable DOD in the tune and modified the idle to 1125 rpm at -40 to engine temp 850 rpm. I never get to 850 rpm though which may or may not be a concern I don't know. It is running rich most of the time and still has an extremely rough idle.

Should I modify something under the airflow tab? Or because its running rich lower the fuel in relation to the airflow? Is there a process for tuning STFT/LTFT that is followed when not using a wideband?

How do I identify in the scanner when you are consistently running lean? Is there a way to setup a gauge that shows how rich its running?

Another thought I had was to zero out the long term fuel trims and allow short term to rebuild the table (I think I saw something like that in a video). I still have to pump the pedal quite a bit to get in started but it runs after starting (just rough). I'm completely new to tuning but have been trying to read and study everything I can find that relates. I would appreciate help with the process I need to go through to get idle and airflow dialed in a closed loop system.

My As Found file is what I read from the vehicle after disabling DOD and I have attached 2 log files of letting it idle with the scanner. I'm still trying to learn so any direction with this is really helpful.

[dhoagland]

See if that helps
I adjusted the MAF Low table based on your scan. I also hit the VVE, but only in the idle areas your scan created...

This is only to test the idle just as you performed it before, kind of a "Start up Estimation"

I set your idle to the 850 you wanted (if you will look your Park/Neutral was set to 950
I set it to MAF only (Your MAP reading seemed high, I think this will remove it from the equation)

What are the durations on your cam?
If it isn't too much more than stock you could have other issues (assuming it was good running truck before failure)

For your questions
Yes you can adjust your air flow using LTFT/STFT math... But only light throttle/idle, for PE you will need a wideband

[lumberjacked]

The cam is a BTR low lift truck cam 224/230 112+3 .500 lift. The truck was running great before all the round 2 problems of another collapsed lifter. Ive never had any issues with the engine in the last 6 years, except the first collapsed lifter and now the 2nd in the last 6 months.

Can you explain to me what this means so I can go study up on it "I set it to MAF only (Your MAP reading seemed high)"? Specifically why setting it to only MAF removes MAP from the equation.

I broke down and bought a wideband today. I didn't want to because this isn't a truck I want to be constantly tinkering with, but it seems to get this running better I needed too.

[dhoagland]

Yes...
There are really good Videos and write ups out there... Goat Rope Garage u-tube are pretty straight forward and easy to follow.... I looked at some logs with Cams added, your MAP might not be as far out of line as I thought...
To set MAF only
>Engine > Air Flow > Dynamic > Dynamic Air Flow, High RPM Disable to 400 High RPM Enable to 390

If you have your file open in the editor (and download the one I sent). You can go up to the top commands and click "Compare".. In the drop down click "Open compare file" and go to the file I sent you and select it...
Then the 3 menus
Then you go back to the "Compare" button, click it...Then go to "View comparison log"... All the differences between the 2 tunes will be shown... You can click on them and it will open the tab in the editor...
On the top menu between the "Folder Picture" and the "CF" you will see three buttons with lite up stars (blank before you opened your compare file)
The one on the left is the first file you opened, the middle is your compare file, the one on the right will show differences in individual tables that you have opened...

[hjtrbo]

Hope this helps you out. Should be close.

Have a geeza at this one.hpt

[dhoagland]

Hope this helps you out. Should be close.

Have a geeza at this one.hpt

Nice
I see you hit alot of the idle tuning stuff too

[2xLS1]

Me thinks you don't really understand the size of the cam you bought.

[hjtrbo]

Me thinks you don't really understand the size of the cam you bought.

She's got some chop in his log. Probably sounds good and shakes the truck around 😁

lumberjacked; Couple of things to note in my suggestion tune for you... I only touched your maf in your idle area and blended up. Only once you get a few drive logs in will we know how far out the cam has put your fuelling. If it is way out then you will need that wideband installed. Dont do any power pulls till we know. Your MAP is reading quite high at idle so it needs a little more timing in the idle table around the idle cells, i didnt add this in to your tune. Start with 16deg and blend out around it. Do a blend copy of only the changes to the coast down table too. You cant put to much timing in as once you get to around MBT your idle spark correction wont work.

For your next lot of logs please add the following:
Delivered engine torque
Adaptive spark
Idle minimum air (you might not have this one)

Your method of starting the truck and walking away to get your idle log is good. Makes it easy to see what's going on.

[2xLS1]

The lift on the cam is exactly the same lift as before .500.

Why me thinks that.

[lumberjacked]

Why me thinks that.

You are right I do not know exactly what I bought. I took a chance when I made the jump to do a cam swap and learn. I followed an article of a guy that did the same work on the exact same truck that had a failed lifter. But for my own education can you explain to me the differences from the original cam. Maybe I was way off thinking the lift was the same but the duration being different.

[lumberjacked]

I'm going to try and get the wideband installed this weekend. I'm still unsure if I can remove one of my o2 sensors and use the bank or if I need to have a welder add the extra bung. Ill add the extra channels. I'm replacing the transmission cooling lines this weekend afterwards ill collect the driving logs.

[dhoagland]

I'm going to try and get the wideband installed this weekend. I'm still unsure if I can remove one of my o2 sensors and use the bank or if I need to have a welder add the extra bung. Ill add the extra channels. I'm replacing the transmission cooling lines this weekend afterwards ill collect the driving logs.

You can add the wideband in place of one of the upstream o2 sensors, obviously you would then tune in open loop...
If it was me I would get relatively close using your o2's and LTFT/STFT Math... I say that for 2 reasons, 1- it will insure everything in your system is working correct. 2- My wideband manual suggested that fueling too far off "could" damage it...

It would not hurt to throw the tune in that @hjtrbo sent... He modified some idle timing/correction stuff that should help a bunch..
If that heads you in the right direction it kind of indicates mechanically everything else is okay and I think its a good "Start up" point

Keep us informed

[lumberjacked]

I did not run the new tunes this weekend you guys gave me because I think I have discovered some more problems. When I went to get the truck ready to flash and drive it down the road I noticed the brakes didnt have any boost. I ended up hooking a vacuum gauge to the intake and its reading super low around the 5-6 range, which from my understanding is an intake leak or an intake gasket leak. But I'm curious because in the logs you guys have been telling me that my MAP is really high.

When I look up symptoms I get - The Manifold Absolute Pressure (MAP) sensor is a key sensor because it senses engine load. The sensor generates a signal that is proportional to the amount of vacuum in the intake manifold. Are these two related meaning the logs all along were telling me that I didnt have good vacuum to begin with?

I'll replace stuff in the next few days and hopefully get back to the tune.

[2xLS1]

Map reads in kPa which is in metric. A high kPa number is low vacuum in psi.

[dhoagland]

In your Channels you can right click on your MAP, Select units, select PSI and the units will change...
I did it in your log and the section I was on was 9 PSI...

Then I change it to inches of mercury and it was 19.5...