HP Tuners part 2

[Redog]

OK So Paul, (MMG) explained to me the power of scaning and histograms and I was doing pretty good for a while, but I think I goofed up and reversed the progress I made :(

I was just tuning my MAF and Paul said to get everythng as close to 1% as possible. I had the car running pretty good until the other night. I had all negitive numbers in my scale across the board from 1800 to 6250 Hz, so I changed them to a postive number and got numbers (at first I got all zeros in the MAF scale) after I sent it to the car, the car wouldn't start. It cranked, turned over, then stalled :eek:

I put the previous MAF scale back in place and the car runs, did another scan and got MOSTLY negitive numbers across the board, but I left it alone.

I know it's backwards (thus why I tried to change it to postive numbers with a "paste speical" 'add' command) because when I floor it, the car leaned out, and when I'd get off it it would run rich (sitting at a light it would go to about 13.1 on the WB, sometimes 12's)

So how do i correct?

[MMGT1]

You are dealing with percentages bud, not whole numbers. "Paste Special Multiply by % half"
Get a fresh scan. When you connect open the VCM Controls, under fuel click on "Reset Fuel Trims" once.... only once. Drive for a good 10-15 mins then start your scan. Drive for a good 15 mins or so then copy the results in the trim histo to the maf table by %1/2. Repeat until you have your trims back in line and as close to 0 as possible. Mine are 0 to .6 so you know how close it can be tuned.
Also, you never want to see any negative trims in our PCM's. If the computer locks a negative trim before going WOT it will remove the error it see's from your PE mode through the entire run. In other words, if you have negative trims, you will go lean when WOT. When you get your MAF reading that close to 0 trims it will lock in at 0 trims in PE and the result is exactly the fuel you'd tune every time.
And again, only reset the fuel trims once. Not with each scan.

[MMGT1]

Here's what your idle will look like when you are done.
http://i823.photobucket.com/albums/zz159/MMGT1/HPTuners/th_Idle_with_36lb_injectors.jpg (http://s823.photobucket.com/albums/zz159/MMGT1/HPTuners/?action=view&current=Idle_with_36lb_injectors.jpg)

[Redog]

OK!! Thanks!

I knew I did something wrong.

I usually see negitive numbers in my histo. When this comes up what should I do? Trim around them?

[MMGT1]

Just use that histo and they will come in line within three scans man

[Redog]

Off tomorrow (got a weird shift this week) so tomorrow is tuning day :)

[Redog]

You are dealing with percentages bud, not whole numbers. "Paste Special Multiply by % half"
Get a fresh scan. When you connect open the VCM Controls, under fuel click on "Reset Fuel Trims" once.... only once. Drive for a good 10-15 mins then start your scan. Drive for a good 15 mins or so then copy the results in the trim histo to the maf table by %1/2. Repeat until you have your trims back in line and as close to 0 as possible. Mine are 0 to .6 so you know how close it can be tuned.
Also, you never want to see any negative trims in our PCM's. If the computer locks a negative trim before going WOT it will remove the error it see's from your PE mode through the entire run. In other words, if you have negative trims, you will go lean when WOT. When you get your MAF reading that close to 0 trims it will lock in at 0 trims in PE and the result is exactly the fuel you'd tune every time.
And again, only reset the fuel trims once. Not with each scan.

OK If I'm reading this correctly.

Connect
reset fuel trims (only one time)
drive for 15 mintues (at least)
start scaning
drive for 15 to 20 minutes (at least)
open histo MAF table and paste by 1/2%
download to car
drvie and scan again

Now do I use the SAME histo as before, or the new histo created by the second scan? and then the 3rd scan?

And I only want to play around with MAF Hz below 7500?

[MMGT1]

You got it man, and always use the results of your latest scan and copy the error reported from that. Make sure you are using the "Average" reported values.
The 7500hz value.... what you really need to do is find the hz value where you go into PE mode. You can easily see that in the scan through the chart view. From a dead stop, accelerate fairly aggressively. Go as high as you would safely go in the RPM range. Then go back over your scan and move your cursor over the spot on the table where your 02 readings go solid, when 02 stops switching and runs solid is when you are entering PE mode. With your cursor line at that spot what is your MAF reading in hz? The "switch point" is what you can tune up to using that histo. Most I find will switch between 7 and 7500, but each car is a little different. Don't be surprised if its a little lower. Once you have your MAF set to that point, ie: all values in that histo reads within a % or so, look at the MAF table in your tune. Right where the switch point is the graph will either dip or rise a little, the break in the scale will stick out to you. If you need to add let's say 10% at the break point to make it smooth out there, then add 10% from the break point to the end of the scale to make the curve smooth to the end of the table. This will get your PE mode close and at least safe. Then connect wide band and use the WB to properly set up your PE mode. Make no changes below that break point with a WB.
Now, here's why.... V6's are a pain in the ass to tune, no other way to put it man. You cannot tune the entire table with a WB like we do with the newer v6's and v8's, when you put the narrow band back into play, the difference between the WB and NB will be at least a couple of % error between the two. In a v6 any error that is reported will carry through the PE mode. If the car is pulling fuel right before PE then it will pull fuel through your run making you go lean, and if there are positive trims the the car will go rich through the run. So, a rule of thumb is NB for cruise and WB for PE mode.
Now, don't get freaked out with the NB's, they are EXTREMELY ACCURATE at 14.7:1 That's what they are made to do, read stoich very, very well. Its when a NB gets outside 14.7:1 is when they are no better than a guess! This is where your WB shines and you can use it to tune your AFR in PE. Hope this makes sense... lol... ask away man...

[MMGT1]

Quick question, how did you set your wide band up? You have a designated bung that your WB is in or you are switching it out for the NB for tuning? How are you logging your WB in HP tuners, through the handheld or through a sensor?

[MMGT1]

Here's a bit of reading about NB vs WB sensors...

http://www.hptuners.com/forum/showthread.php?p=69805#post69805

[Redog]

No I have the WB O2 in a bung, in front of the cat, right where teh exhaust exits the engine bay

[Redog]

So I reset the fuel trims, did the scans

Latest scan, the histrogram was 2.8 2.4 then 2.0 starting at 1875, after that all the numbers were negitive. I didn't trim anything, but i was going to trim the first three cells and leave thr rest alone and do another scan

[MMGT1]

You say negative trim, how much negative? Within a couple of %?

[MMGT1]

Idle trims are a bitch, no two ways about it. I'd leave the idle alone for now and get the rest as close to 0 as you can, then WB dude!! Sounds like its really finally comming together for you! Then we can tackle timing... oh the joy!!!!!!!!!!! ..... LOLOLOL

[Redog]

I saw as low as -.02 and as high as -4.5

[MMGT1]

4.5 is too far out of line. Give a couple more runs and get it tighter in those regions man. Within 2% and Im happy and it will lock at 0 trims WOT

[Redog]

I'll run a few more scans on Saturday.

The current scan I have has 1875 to 2100 Hz all postive, but the rest is WAY out. I did one scan and everything was WAY OUT like that, did another scan and everything was WAY IN by the same numbers.

It was like Redog took all those negitive numbers and made them postive, becasue the numbers were the same, just postive :lol:

[MMGT1]

Red, is your EGR still in the car or not? If it is, did you dissable it for tuning?

[MMGT1]

Shoot me a copy of your latest scan bud, let me see where you are at with this

[Redog]

No I don't disalbe the EGR for tuning. Should I?

Lastest scan, all values in the histogram were negitive. I scaned it a few times and got the same results :banghead:

[MMGT1]

Yes Red, for tuning set your EGR to the highest temp possible. The EGR is going to mess with you big time for tuning. Tune your trims then you can re-enable the egr if you want to get your mileage back a bit. Mine's out completely....
I got thinking about yours and the only reason, other than a leak, had to be the egr messing with you. Disable that EGR and Im sure you'll nail your trims. Remember a little negative is good, but within a couple of % its going to lock at 0 and be good for you anyway

[Redog]

You saw that Histo, they were all negitive, I trim them as well?

:eek:

[MMGT1]

yup, you get my e-mail on how to shut down that egr to tune it?

[Redog]

Yeah I got that email.

Just need to know where to find the EGR at in the tuners. I'm hoping to get my ass out of bed early enough tomorrow to start tuning

[MMGT1]

Engine/General/EGR Min IAT/ < set to 284* This will dissable the EGR function for tuning. When you are done, then you can set it back to 32*

[Redog]

It was already set to 284* Now I know why I've had such crappy MPG lately :dry:

I did another scan today and all the numbers where still in the negitive range. I should not trim a negitive nukber into my tune, correct?

My 1875 Hz number was -10.8 :eek:

I'm doing these tunes in a 15 minute drive, do I need to drive longer?

[MMGT1]

Put in what it reports as a trim, be it negative or positive. 1875hz is real low in the table. With HP you do not have control over timing at idle and adaptive idle is going to mess with you pretty good. You can control OL fuel commanded now though which is nice. Have you gotten into those tables yet? Most of the pro's will recomment that Idle region be left alone and only tune off idle and WOT with the v6 unless you are running a VE tune only. In our PCM I do not recommend an OL tue as your car has to be on SD mode to run OL. If its not banging gears, you are not really in OL.

[Redog]

OK I'll trim all the negitive numbers to the MAF table and do another scan on the way home from work tonight. Last time I trimmed all negitive numbers, the car wouldn't start, that's the thing that scares me :eek:

I haven't touched anything else in the tune yet.

[MMGT1]

are you working with the same math system bud? Scanning in Imperial and tuning in Imperial or doing both in Metric? This should have been a snap for you. Seriously a couple of runs and it should have been spot on. I got a feeling you are scanning in Metric and applying to a Imperial view table set up....

[Redog]

I'm pretty sure the scanning is in Imperal, I'll check later (at work now)

I didn't even know there was a different tune set-up :wacko:

[3500Alero]

Hey Paul! can you post up that link for the wide band you told me about?:cool:

[MMGT1]

http://www.bmotorsports.com/shop/product_info.php/products_id/357

Best there is short of investing 12-15 grand in a lab grade one bro!