Improving WB Tune: Large difference in Min/Max + Suggested Values for TC+TF

[2002_z28_six_speed]

Hi,



I have had EFI Live for years but never used it much.


I am trying to tune my truck and I notice massive differences in the min/max on all recorded cells. Even with the filter suggested in the tutorial. I am talking about .800 to 1.2 in the same cell.

Is there a method to tighten up recorded values? I ask because in the past, I used to play a game where I would apply BENS time and time again and it would just overshoot my intended AFR. Flip from too rich to too lean. I never got to the .01 goals in tutorials.


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Also, could anyone suggest TC or TF values for my truck? I still get surging and stalling. I followed the guide posted on the forum but I am just not there yet.
I have a 224 texas speed cam with headers on a LQ4.

I don't expect anyone to do my tuning for me but a roundhouse kick in the right direction would really help out!

{removed tune file from this post due to not being relevant anymore.}

[RADustin]

are you sure you are OL? log STFTs to be sure.



You have way too many PIDS to be high speed- this could be another issue. get your VE spot on, then worry about idle.

[RADustin]

what do you mean by choke? too much air?

There is no reason why RAFIG will not work- unless your VE table is somehow way off. How much RPM fluctuation do you have at idle?

I had major issues with my TF and TC upon decel my engine would literally turn off. I could fudge the idle air flow tables high and it would help, but as soon as the truck learned it's way back down it would be crap again.

Eventually I figured out my issue was in 99 the TF and TC tables looked much different than the 2002 tables. Once I copied over my 99 tables into my tune it brought it within 90% of perfect, I only needed to tweak a little to loose a slight hanging idle.

I mention this because my cam is much larger than yours, and really didn't need much different TF/TC tables from stock- but I do know my rolling airflow is perfect. I also have timing set to idle as strong as possible(right under most vacuum).

If you have changed TF and TC far from stock you may want to back track and revert back to stock and attempt again.

I did also have an issue where a limiter was limiting how much airflow I could add via TC and TF. I can't find this limiter now but I will keep looking to see what I changed. This was the last straw- once I raised that limit my TC and TF were moving as commanded and the engine was running great.

[joecar]

This is the key:

...

Eventually I figured out my issue was in 99 the TF and TC tables looked much different than the 2002 tables. Once I copied over my 99 tables into my tune it brought it within 90% of perfect, I only needed to tweak a little to loose a slight hanging idle.

I mention this because my cam is much larger than yours, and really didn't need much different TF/TC tables from stock- but I do know my rolling airflow is perfect. I also have timing set to idle as strong as possible(right under most vacuum).

If you have changed TF and TC far from stock you may want to back track and revert back to stock and attempt again.

...

[RADustin]

Joe I am loosing my mind looking for the value I changed to allow for more TC+TF.

Do you know where this value is? I remember being out on the road(I tuned my truck during a 3500 mile trip) and finding a 'maximum idle ETC contribution' or something and upping it. Before my TC+TF was getting clipped down.

It would be similar to B4370 but not specifically for a/c. I think it was for commanded TP of 0 or something.

[joecar]

I'll look thru my tune files to see if I can find what you mean.

[2002_z28_six_speed]

I have been doing a lot of work on this and making some progress.

The truck doesn't stall as much anymore. Only sometimes randomly and multiple times in a row. It used to stall going into R and now it doesn't.
Every once and awhile the idle RPM will get batted around a whole bunch and take 30 seconds to settle down. 200 RPM differences.
Sometimes when letting off the gas on a roll the RPMs will come down to idle, bog, and then pop back up.


I reverted some tables back to stock and then added some throttle follower at higher amounts of attack.
Working on trying to find the right cracker values.
Not really sure on the Desired airflow. Tuning with RAFIG still seems to make it worse.
One thing that really bugs me is that when doing a wideband log of 20 minutes or more I will see a max and min in a cell of .8 to 1.1 ben or so. The range of values recorded isn't very tight. Generally tuning with BEN seems to work.

[2002_z28_six_speed]

You know what is weird?
Things will be running great and then every once in awhile the truck just takes a dump. Can't ever figure out why. Then I will walk into a store and come back. Truck runs great. Same weather, same ECT.... Can't figure it out.

[joecar]

Hmmm... Check all the grounds, make sure they have zero voltage drop with engine running.

[RADustin]

what happens when it dies? can you snap shot your log?

does MAP and spark remain the same and it just die off? MAP rise to ambient? spark drop out?