Don't know what to do

[shady1504]

Ok I just got hptuners for my 2000 LS1 and I have no idea how to tune it. The only stuff I have figured out is gears and fans. My mods are SLP(lid, cold air, maf, LS6 intake) MSD wires, longtube headers, o2 sims, off road y pipe, 3 inch exhaust. My car is automatic with 3.42 gears. When I dynoed my car I got 345hp to the wheels and it was running rich. So can anyone help me with what parameters I shoud be changing? Also whenever I run the scanner I try to save my histograms but when I try to load them up again they are just blank. Any help would be appreciated. Thanks in advance.

[crewchef]

Check the sticky in this forum and also the one in the GM V8 Tuning forum. You might also want to read stickies over on www.ls1tech.com under tuning.

I'm not too far ahead of you, I've only had HPT for about 3 weeks now. Just take your time and spend a lot of it reading the posts on here and on LS1tech. It won't take you too long to be knee deep. I'm trying to read/learn enough to understand how particular tables interact before I try adjusting them. I generally try to make small adjustments to see if I get anticipated results before I actually try to go for a "final" tune.

I had the same problem with the histograms. Not sure if this is correct/best way but it's what I've been doing. Just open up your saved log file and play it back. If you bump the play back speed up to 10 it flys by and will fill in your histograms for you with the logged data. I believe saving a histogram itself is simply saving the configuration for the histogram itself and not the data.

Edit - read another post that gave me new info. Open Histogram, right click and select load all data. Fills in the Historgram from your open log file without having to play it.

[shady1504]

Ok I started doing my ve LTFT but I'm not sure if I'm doing it right. I've done the process about 4 times now logging then adding values according to the scan. But the values on my table are up in the 90's now, so I'm wondering if I'm doing it right, at stock the values were in the 60's. On the histogram if it shows like a value of 10 I'm supposed to add that 10 on the editor right? Thats what I understood from reading the help topics. Well I hope someone can give me some advice. Thanks

[brh26]

Hi,
welcome to the black art of tuning!
The VE table adjustments tend to work in blocks. What this means is, that adjacent cells influence one another. In general, if you have a value of +10 in a cell or group of cells, I have found if you adjust the surrounding cells by half of that value(in this case, add 5) then reset the LTFT's in the scanner then go for a logging session, the LTFT's should be getting close to 0. If you have increased the values from 60 to 90 or more, you have gone too far, and may have a mechanical fault causing the LTFT's to remain high. You are resetting the LTFT's each run?

Brian

[shady1504]

No I haven't been resetting the fuel trims because the steps didn't say to reset them each time.

[horist]

Which directions are you following?

http://www.hptuners.com/help/vcm_edi...dvanced_ve.htm
says ot rest fuel trims

if you're using
http://www.hptuners.com/help/vcm_edi...to_user_sd.htm
Then that's open loop (needs wideband)

[shady1504]

These are the steps I've been follwing:

A. In the VCM Editor>Edit>Engine Diagnostics>General>MAF Sensor Fail Frequency = 0. This will set a P0103 code and turn on the SES light. Ensure that the P0103 DTC is enabled and you are seeing P0103 in the DTC list. Don’t worry about the DTC at this time.
B. In the VCM Editor>Edit>Engine>Spark Advance>Main Spark vs. Airflow vs. RPM Open Throttle/Moving. Copy the High Octane table to the Low Octane table. The computer reverts to the low octane table when a MAF failure is indicated, this will assure optimal timing. 
C. Start the VCM scanner>Histogram display. File>Connect. Then Tools>VCM Controls>Fuel & Spark>Fuel Trim Learn>Reset Fuel Trims.  
D. Changes to the LTFT’s do not take effect immediately – the PCM requires about 50 minutes or roughly 100 miles to allow for the PCM to relearn the fuel curve. Try not to enter PE mode while driving and logging for this procedure. Log about 30 minutes of driving at many different speeds and conditions. Try to hit as many cells in the histogram as possible. Stop logging and save the log. Do NOT turn off the engine until the log is saved or it will be lost. Go to VCM Scanner>Histogram display>LTFT's. Open the VCM Editor>Edit>Engine>Airflow>Main VE and select Primary VE vs. RPM vs. MAP.  
E. The goal is to get ALL LTFT’s between -5 and +5. Positive LTFT's indicate fuel is being added because of a lean condition. Richen this cell by increasing the VE table value by the amount of the LTFT value. The operation is opposite for negative LTFT's. 
If LTFT = (4), VE cell value is 67, result would be (67)+(4)=71 - increasing the VE, which is adding fuel. If the LTFT was (-4), the result would be (67)+(-4)=63, decreasing VE and thus reducing fuel. To decrease LTFT values, a smaller number or number closer to zero, ADD the difference between the positive LTFT value and zero to the corresponding cell in the VCM Editor>Edit>Engine>Airflow>Main VE>Primary VE vs. RPM vs. MAP table. To increase a LTFT value, a larger number or number farther away from zero, SUBTRACT the difference between the LTFT value and zero and SUBTRACT from the corresponding cell in the VCM Editor>Edit>Engine>Airflow>Main VE>Primary VE vs. RPM vs. MAP table. For example, In the VCM Scanner>Histogram display, the (.8, 40) cell, 800 RPM's and 40 kPa, is 4. To bring the VCM Scanner>Histogram display>LTFT cell (.8, 4.0) DOWN to 0 from 4 ADD 4 to the (.8, 4.0) cell in the VCM Editor>Edit>Engine>Airflow>Main VE>Primary VE vs. RPM vs. MAP table. If the VCM Scanner>Histogram display>LTFT cell (2.0, 30) is -10, SUBTRACT 10 from the (2000, 30) cell in the VCM Editor>Edit>Engine>Airflow>Main VE>Primary VE vs. RPM vs. MAP table to bring it UP to 0. This will not work out exactly but will be VERY CLOSE.
F. Repeat steps D-F until ALL values in the VCM Scanner>Histogram display>LTFT are between -5 and +5.  Try to complete this on the same day for best results as LTFT values can vary +-4% per day.  

[shady1504]

once I add the values, reprogram it with those values, repeat the steps and reset the fuel trims and start scanning again I would expect the new values on the new scan to be a little bit lower but some are higher than before.

[crewchef]

Remember I'm a noobie too but here's something to look at.

Does your 2000 have a Secondary VE? If so, you need to adjust that table with the same numbers and in the same way you adjusted the Primary. If you have a Secondary table the PCM uses this table when the MAF fails, or in this case is turned off. You could just keep right on tuning the Primary and never see any changes at all. The Secondary is half resolutin as compared to the Primary, it's MAP cells are in increments of 10 instead of 5. I just cut/paste each row from the primary into the secondary.

If you have saved all the four different tunes (.bin) you've done after eaching logging then you might want to go back to the initial tune you did after the first corrections. Use the cells in the Primary to update the Secondary and then go log some more. If you don't have the first tune you might want to consider starting all over with the stock tune. If you tried to use numbers you've already adjusted four times to update the Secondary you may be so far off it's going to be harder to get it right than starting from scratch.

[shady1504]

Yes I do have a secondary ve but I've never adjusted it. I started over yesterday and did two tunes. I did a third but I haven't uploaded it to the car. So should I just copy the primary table to the secondary?

[crewchef]

Yes, copy the matching rows over 20, 30, 40, etc. Reset your LTFTs and go do some logging, should see affect of changes on LTFTs after updating secondary table.

[shady1504]

I was wondering since I have my buddy's stock tune if I could copy his ve table to mine? What would be the difference? He has an 02 m6 LS1.

[crewchef]

I wouldn't think you could just take someone elses tune and copy it into your tables. Every car seems to be different even same year model. Then you have to figure out what mods you have and he doesn't, etc....

Just keep reading and working with it, you'll get the logging figured out and get some good data that you can tune your VE tables with. There's a little learning curve but you'll be happy when you've got it. Then you can move on to the next thing and get confused all over again.

[jlee41]

no expert myself but was having the same issues whne i started and realized that I had to adjust both primary and secondary ve tables. Once I got my head out of my @ss then it started workin out alot better. The process of learning I guess..