Help with tune adjustments

[SuperChevy]

I have recently upgraded the computer on my 97 K3500 to a 411 PCM. I installed a custom os and copied the calibrations from the system loaded on the PCM when I bought it (express van). The truck idles good but stabbing the throttle causes the engine to bobble really bad. If I keep it under 1/4 throttle the engine revs up without bobble. At WOT it bobbles for a second then runs strong- anything less than full throttle results in a continuous bobble almost stalls completely.
I am hoping to get some insight on which parameters are out of line- see attached tune and log.

Some info on the truck:
97 7.4L Engine
Ported heads
28lbs injectors
whipple super charger- old school with two addition 50lbs injectors at the throttle body
Granatelli MAF
Gibson Headers
High Flow cats
4:56 gears with 35" tires


Any help pointing me in the right direction would be greatly appreciated since I am new to self tuning.

[L31Sleeper]

Get rid of the Whippletronics it will continue to be a nightmare.
Check out this file.

-Justin
Justin@EFIMuscle.com

[SuperChevy]

L31Sleeper,
Good call on the whippletronics.

I cut them out of the loop and truck runs like a striped a$$ ape again. I appreciate your input and help. I loaded your changes to my calibration as well and seems to work good- the truck has been sitting for 4 months so I need to go spend a couple days salary and fill the tank with some fresh gas (predetinating under load right now) but I can at least have confidence that I can now go farther than a block from the house with the new PCM and tune.

Thanks again
Garrett

[L31Sleeper]

Do you have a 2 bar MAP sensor ?? Your tune is not setup for one.
If you have one I could simply change the tune, If not you will need one.

-Justin

[SuperChevy]

I changed the MAP to one from a Cobalt which I thought was a 2bar sensor but when I scaled the MAP at 190 the tuck would not start unless the throttle was at 50%. Right now it shows 4.8v and 15 lbs with the scaler at 94- I dont know enough about the sensor to know if thats indicative of a 1 or 2 BAR sensor.
G

[L31Sleeper]

That is a 2 bar sensor for sure, What is the MAP reading a 15lbs it should be between
200 and 210 KPA. I would try going back to 190.

-Justin

[SuperChevy]

At key on engine not running the readings on the pid are as below.
GM.MAP =4.8v and GM.MAPBOOST_DMA =15.2lbs
The dashboard says it reads the MAPBOOST PID as kpa but the data tab shows that sensor as psi. I will upload the calibration with the scaler turned up again to see what happens now that the whipple computer is not in the system
Thanks
Garrett

[L31Sleeper]

At key on engine not running the readings on the pid are as below.
GM.MAP =4.8v and GM.MAPBOOST_DMA =15.2lbs
The dashboard says it reads the MAPBOOST PID as kpa but the data tab shows that sensor as psi. I will upload the calibration with the scaler turned up again to see what happens now that the whipple computer is not in the system
Thanks
Garrett

HA Ha.......well if you are making boost with the engine not running I wanna know your secret !!

[SuperChevy]

So maybe I misread the data- the MAP boost pressure read the same as the BARO with key on- I assumed it was reflecting atmospheric pressure as I am in the 714 and close to sea level. I loaded the tune with the MAP scaler at 190 and the truck runs but idle is very rough. However after the flash my scan tool is not scanning anymore it has started giving an error of "no response from vehicle" when I push the yellow button to start monitoring. The learning curve continues.....Ill work out the scan issue and work on the idle but at least its running better now that the whipple stuff is out of the way.

[L31Sleeper]

Now that it's set to 190 how does it run under power ??
Do you have a Wide Band O2 ??

-Justin

[SuperChevy]

It screams wide open (Today was the first time that truck has ever broke the 35" tires loose shifting to second). After warm up it wont idle at all and I have to keep the throttle cracked to keep it running- by the stuff spitting out the exhaust I am guessing that it is getting too much fuel at idle. I do not have a wide band sensor but am planning on ordering one so I can make all the fine tuning adjustments.

Any insight to why the idle would be so radically different between the scaler at 94 and 190?

[L31Sleeper]

Any insight to why the idle would be so radically different between the scaler at 94 and 190?

Yes it will use a different part of the VE table (part with less fuel) However it won't do
as good under boost. I modified the VE table and kept the 190 change.
If you get the scan tool working log Injector duty cycle, you might need bigger injectors.

Check it out
-Justin

[slows10]

Try doing a log with 24 channels or less. I opened your log you posted a few days ago and you had 73 pids selected. Thats way to many. It slows down the frame speed a ton. Log the fuel trims. You can get alot closer than you are by logging those.

[SuperChevy]

Okay loaded that tune and same thing I tried -10% changes to the VE up to 30% and did not notice any improvements in the idle. I reloaded the 94 tune so we can take the truck out for the night and will do some more research into my log issues and try to get the duty cycle and fuel trims and lean down the things I log and try to post in the morning.
I really appreaciate all the help everyone is giving.

[slows10]

Is the maf disabled. Maybe someone like joecar will chime in and help. This tune looks a bit screwed up to me.

[joecar]

Regardless of anything, fix these out-of-range values before doing anything else:


Out of Range calibration summary: 04:05:22 pm, Sunday May 29, 2011

Engine Calibration.Fuel.DFCO
{B3308} DFCO M6 Enable Temp, was out of range when loaded.

Engine Calibration.Fuel.Mixture
{B3614} Hot PE Mode Coolant Temp Threshold, was out of range when loaded.

Engine Calibration.Fuel.Lean Cruise
{B3636} Vehicle Speed Lean Cruise Enable, was out of range when loaded.

Engine Calibration.Abuse Management
{B1207} Abuse Management Vehicle Speed Threshold, was out of range when loaded.

Engine Calibration.Shiftlight
{B5802} Min Temp to Allow Shift Light, was out of range when loaded.

System.Fans
{G0903} Fan #1 Turn-on By A/C Temp, was out of range when loaded.

Also A0012, A0013.

[slows10]

Also maybe you should stay out of boost until you get a wideband and get that tune looked at.

[joecar]

+1 need a wideband.

[joecar]

B0101 VE does not look right... after 4400 rpm does torque really drop off that quick...?

[L31Sleeper]

Is the maf disabled. Maybe someone like joecar will chime in and help. This tune looks a bit screwed up to me.

I'm just trying to get something that will run so he can take it from there.

I thought something was out of range but the software has changed.......I didn't realize that you have to push the refresh button, before you didn't, it just showed the list ??

We still need the scan tool working to verify MAP function.
Garrett be careful running that tune with the MAP at 94 it might run lean ??

-Justin

[slows10]

I was just wondering what kind of tune this is? Is it supposed to be open loop speed density?

[slows10]

If it is open loop speed density, is the maf failed correctly? Making changes to the ve table wont have any effect if the maf is still working. The op says he was removing up to 30% fuel from the ve table and it has no effect. I think there is more than one table that needs to be changed to disable maf.

[L31Sleeper]

I mentioned the Wide Band O2 a couple posts back.

[slows10]

I mentioned the Wide Band O2 a couple posts back. So what ?? lol I didnt say anything about whether or not you told him to get a wideband. Im asking questions about what this tune is. ol cl sd maf? Im not making changes to his tune. Is the maf disabled in this tune?

[L31Sleeper]

WOW !! don't take ANYTHING I say personal

The MAF is enabled and the VE IS still factored in the values are combined by the ECM.
It is open loop right now, I didn't set it up that way.
At first I thought he was on his way and needed some help, once I realized he didn't have
a WBO2, I started thinking he should get all that stuff in place first.


-Jusitn

[slows10]

My thinking was that this is a COS tune and the maf is supposed to be disabled in a 2 bar speed density tune? Also in a regular tune with the maf enabled closed loop, you can add as much fuel as you want to the ve table and it wont make any difference. But if you add fuel to the maf table it will make the afr richer.

[L31Sleeper]

My thinking was that this is a COS tune and the maf is supposed to be disabled in a 2 bar speed density tune?

It doesn't have to be Speed Density, It is currently a 2 bar Open Loop MAF tune.
COS Allows you to remove the MAF without being stuck with the Low spark table,
you are not required to disable or remove it.


Also in a regular tune with the maf enabled closed loop, you can add as much fuel as you want to the ve table and it wont make any difference. But if you add fuel to the maf table it will make the afr richer.

Well any Closed Loop tune is going to try to stay Stoich that is how trims work.
B0120 determines the RPM at which the ECM will use the MAF reading Exclusively if not disabled.
So if you set B0120 to Zero the ECM will use the Only MAF data, if you set it to 12,000 RPM then
the ECM will AVERAGE the VE and MAF data.

-Justin

[L31Sleeper]

Peace Out
-Justin

[joecar]

So engine idles, but stumbles when opening throttle...?

Can it maintain steady speed at some load while driving...?

Maybe try this:
A-New-Twist-on-CALC.-VE-Table..Computing-the-Entire-VE-Table (http://forum.efilive.com/showthread.php?15236-A-New-Twist-on-CALC.-VE-Table..Computing-the-Entire-VE-Table)
(summary notes says to set B0120 to disable VE while doing this).

[SuperChevy]

The engine runs steady under both cruise and acceleration. When the rpm get down to 1500 it stalls like the key is shut off. Once above 1500 I have not noticed any bobbles or rough spots.

I am ordering a wide band O2 sensor and will get it in next weekend.

Since I am new to this tuning and customizing does anyone know of a matrix or reference source (ie book to read) that would help me get a better understanding of how the tables interact with each other and how changes in the table affect the tune?

[slows10]

Custom OS and 2/3 Bar Tutorial EFILive V7 Tuning Tool
Going MAFless
When fitting a 2 or 3-bar MAP sensor you must disable the MAF sensor. It is possible to leave the MAF sensor in place. This will need to be done on the 85mm MAF as the Intake Temp Sensor is located in the MAF housing. Alternatively, you could relocate the IAT using on older style IAT sensor. Even with the MAF still in place, the PCM must be forced to ignore the MAF signal.
To disable the MAF sensor:
Set the Engine Diagnostics->Engine Diagnostics->MAF->Parameters:
• {C2901} MAF High Frequency Fail 1: 1Hz
• {C2902} MAF High Frequency Fail 2: 1Hz If calibration {C2902} is not available in the operating system that you are using, then ignore this step.
• {C2903} MAF High Frequency Fail Limit: 1
• {C2907} MAF Test Min Engine Speed: 300 RPM
• {C2908} MAF Test Min Run Time: 0.1 seconds
Set the Engine Diagnostics->Engine DTC processing Enablers:
• P0101 ‘C’ Non Emissions
• P0102 ‘C’ Non Emissions
• P0103 This is what I was refering to. The tutorial says the MAF must be disabled. Is this tutorial wrong or out of date? This is why I thought the tune was a bit screwy looking. Did the process change for installing a COS?

[slows10]

Superchevy, is your fuel pressure regulator manifold vacuum referenced?

[SuperChevy]

Yes it has a vacuum line to the intake but as for any more specifics than that I dont know. It is still the stock Chevy regulator and fuel rail there is not much of an aftermarket selection for that engine.

[joecar]

...

Since I am new to this tuning and customizing does anyone know of a matrix or reference source (ie book to read) that would help me get a better understanding of how the tables interact with each other and how changes in the table affect the tune?

This may help:

...

Greg Banish's Tuning Books:
Engine-Management-Advanced-Tuning (http://www.amazon.com/Engine-Management-Advanced-Greg-Banish/dp/1932494421/ref=sr_1_1?ie=UTF8&s=books&qid=1305870247&sr=8-1)
High-Performance-Injection-Systems (http://www.amazon.com/Designing-Tuning-High-Performance-Injection-Systems/dp/1932494901/ref=sr_1_2?ie=UTF8&s=books&qid=1305870247&sr=8-2)

Links on this forum: Tutorials (http://forum.efilive.com/forumdisplay.php?17-Tutorials)

Links on efilive webpage: Tutorials (http://www.efilive.com/index.php?option=com_content&view=article&id=130&Itemid=134)

Also, read the scantool and tunetool user manual pdf's (included with installation of V7 software).

Acronyms: most of these can be found in Greg Banish's tuning books.

[joecar]

Yes it has a vacuum line to the intake but as for any more specifics than that I dont know. It is still the stock Chevy regulator and fuel rail there is not much of an aftermarket selection for that engine.If the FPR is manifold referenced then table B4001 IFR has to be flat (same value in all cells)...

temporarily remove reference hose, measure rail pressure, use spreadsheet to calculate IFR, in the spreadsheet copy the first cell (MANVAC=0) to all cells in B4001.

[joecar]

You can run MAF'd with the COS and boost as long the PCM's 512 g/s maximum MAF flowrate is not exceeded... if it is then you have to run MAF-less.

You are not running MAF-less unless one of the MAF DTC's triggers...

if setting P0103 in C6001 to Non-Emissions does not trigger this DTC, the set it to 1-Trip.

[SuperChevy]

Alright, I turned off all the MAP settings per the tutorial and the truck wont run.

Sleeper was correct that he did not set up the system- it was my first attempt at loading a COS and I obviously got it all twisted. As stated earlier in the thread I bought the PCM with a base tune loaded on it- which did not run well and I assumed it was from the 2BAR MAP sensor, which led to the COS install. Anyone have a 97 454 factory tune on file for comparison? I have my factory PCM on the shelf but dont have a table top set up to scan the factory tune from it.

I do have a couple of questions about going forward from here-
How do I figure out a starting point if I cant get the truck to run in order to get a log when I am using the 2 bar settings?
Can I run logs and VE CALC with the MAP scaled back to 94 and use the wideband to set a base then just rescale the MAP sensor after that or will I have the same issue?
Or do I need to figure out how to get the truck running well enough to run a VE CALC in the 2BAR set up?

Thanks for all the support.

[joecar]

Try the opposite: run from pure MAF, disable the VE table (set B0120 to zero); allow CL trimming (set B4204 to stock); this should get it running even if the MAF isn't stock; use the correct MAP scaler (to match the MAP sensor you're using); you will be able to do the Calc.VET tutorial for CL mode.

New NBO2's might be a wise investment here.

The Calc.VET tutorial will correct the MAF table (to match your MAF) and will calculate the VE table.

But before you proceed, fix those out-of-range parameters:


Fixing Out Of Range Cells:
showpost.php?p=87052 (http://forum.efilive.com/showpost.php?p=87052&postcount=14) post #14
showthread.php?14119-3000-RPM-max-and-setting-codes-03-Z06-with-Magnuson-at-150kPa (http://forum.efilive.com/showthread.php?14119-3000-RPM-max-and-setting-codes-03-Z06-with-Magnuson-at-150kPa) posts #14, #17
showthread.php?14654-I-need-help-getting-the-most-out-of-my-car (http://forum.efilive.com/showthread.php?14654-I-need-help-getting-the-most-out-of-my-car) post#2

How did you apply the COS...? Did you full flash the empty COS and then cal only flash in a calibration...?

Do you have a PCM or calibration file where the truck ran properly...?

[SuperChevy]

I loaded the COS per the tutoral- flash COS then calibration only from the tune that came on the PCM (calibration 12208511 loaded on OS 12212156).

I do not have a file from when the truck ran right because I changed PCMs before I decided to self tune. I have not tried going back to the original tune from the new PCM since I took the whippletronics off. The NBO2s on the truck are still the factory ones so you might have a good point there. I will fix the out or range stuff try running both the original and MAF only set ups and see if I can get log to post.

Thanks

[68sstt]

You can run MAF'd with the COS and boost as long the PCM's 512 g/s maximum MAF flowrate is not exceeded... if it is then you have to run MAF-less.

You are not running MAF-less unless one of the MAF DTC's triggers...

if setting P0103 in C6001 to Non-Emissions does not trigger this DTC, the set it to 1-Trip.

What is the consequences if the the maf pegs out under boost, does the system then revert speed density?

[joecar]

If the MAF pegs at maximum, then that is the value used... stays in MAF'd mode.

[SuperChevy]

Alright- just finished installing a PLX WB sensor. When testing the gauge the truck seems to be running way lean so I am going to run through the calc ve and see what I learn.

[joecar]

Do you have a V1 or V2...?

[SuperChevy]

I am using a V2.

So far I am not getting a reading off the PLX analog out....still working on it

[SuperChevy]

Okay- I was using the wrong PID- i picked the one for PLX and did not select the ext.ADX pid.

[joecar]

The PLX has serial comms output... are you using this to read the AFR/lambda into V2...?

[SuperChevy]

Yes- I am using it to provide afr data to the log.

I do not think I logged the correct info though as I only got zeros in the map- see attached.

1114511146

[SuperChevy]

Alright I got it now- I had accidently selected % when my tune runs with kpa. I am going to get a chance tomorrow to take it on the road and get a log under load.

I do have one question- so far the WB has not sat still at all- it is constantly swinging from 12 to 20 (mostly from 16 to 20). Is this common or is it possible I have an intake leak or some other issue? The tune does not appear to have that rough of a curve in it.


Thanks again for everyones help in guiding me along.
G

[WeathermanShawn]

Alright- just finished installing a PLX WB sensor. When testing the gauge the truck seems to be running way lean so I am going to run through the calc ve and see what I learn.

SuperChevy, the CALC.VE and CALC.VET method of Tuning utilize closed-loop. Your tune appears to open-loop..(see Table B4205).

I have not followed your thread through its entirety, but don't you want the Serial WO2 pids and not Analog?

[SuperChevy]

This is where the newbie would be applied.......I thought analog was good enough to perform a calc.ve- do I need to make the WB feed the pcm in order to be usefull?

[WeathermanShawn]

This is where the newbie would be applied.......I thought analog was good enough to perform a calc.ve- do I need to make the WB feed the pcm in order to be usefull?

No Analog is fine. Its just with the V2 Serial is a breeze. Your Pid list has both Serial and Analog selected..:confused:.

Its the Open-Loop that is the problem. If your are doing CALC.VET you need to be in closed-loop. Perhaps your WB is off because you have are open-loop with both your MAF and VE Table enabled. You can't do that.

[SuperChevy]

I will change up to closed loop and see where that takes me.......I try to only change a few items at a time but I think starting from last best run (then backing up a few tunes- which is a guess) is leaving some unecessary open ends....again- Newbie
Thanks
G

[slows10]

Weathermanshawn, Just an fyi. Maybe you can skim through this thread quickly if you have not read it already. This tune is setup differently than you might be thinking. It confused me for a while.

[WeathermanShawn]

Weathermanshawn, Just an fyi. Maybe you can skim through this thread quickly if you have not read it already. This tune is setup differently than you might be thinking. It confused me for a while.

Hi, slows10.. I agree it is pretty confusing..:confused:.

It really depends on what type of tune the OP really wants. Looks like he might have done some 'mixing and matching' of tune types that is adding to the problem.

SChevy, if you are trying to do CALC.VET we need to do a few things differently. If your doing something else you need to follow their advice. Maybe you can summarize again for us what type of Tune you are going after..

Thanks..:)

[SuperChevy]

At this point, one that runs, with out blowing up. The truck is used for towing a toy hauler and off roading at Glamis/River so it is dual purpose and does a lot of idling in traffic and not as much "racing". I am thinking that if I can get it to run correctly, closed loop would be the best set up. As stated in earlier post the truck has not ran right since I installed the new 411 computer so I am merely trying to get in the "zip code" as one of the books puts it- then I will go from there with working on peak performance.

[joecar]

B3616 is too restrictive for the B3647 you're running; and B3618 is not sufficiently rich.

set B3616 to 60% below 3600 rpm and to 35% from 3600 and up.
set B3618 to at least 1.17 and richer if you're running boost.
set B3647 last 3 columns to same as B3618.

[joecar]

Your B3801 and B4205 don't agree with each other... set B4205 to allow closed loop.

Then set B0120 to zero, and follow the Calc.VET Tutorial.

[SuperChevy]

Joecar,
Thank you for the advice- the truck runs much closer stoic than it did over the weekend. I have attached a short log as unfortunately a longer log came out corrupted and I am out of time tonight for tooling on the truck (5 year old graduated K today). I will try to perform the calc ve table later this week but I am at least in the zip code now.
Thanks again
G
11152
11153

[WeathermanShawn]

SuperChevy, there are still some outstanding issues here...

First you are not using the correct Pids for CALC.VET. You must use the Pids found in this thread: http://forum.efilive.com/showthread....tire-VE-Table. (http://forum.efilive.com/showthread.php?15236-A-New-Twist-on-CALC.-VE-Table..Computing-the-Entire-VE-Table.)There is also a Tutorial found on the bottom of that page that goes into greater detail about Pid selection. etc. I don't know where you are getting your current selection, but its wrong.

Second, with the 2 Bar MAP, you will never be able to get your MAF and VE Table to match. Thats because your MAF flow is way to low for your VE Values. If you look at the attached screenshot, the MAF flow is incredibly low for the MAP. You have a huge difference between CYLAIR.DMA and DYNCYLAIR.DMA.

I think we need to re-look at what method of tuning you are doing. The CALC.VET formula will work for MAF flows up to 512 g/s. That equates to a VE Value of ~ 134%.

Perhaps a Closed-Loop SD Tune would be more appropriate, or something more tailored to your COS..:confused:.