VetNutJim

My BLMs are running from a low (as it can go ) 108 to a high of 120 at all KPA before PE.
I don't have an AFPR installed and don't really want to reduce FP anyway.
Since this seems to be an across the board change I don't want to adjust the VE table.

Is there something I can do with the Injector Constant that will bring the BLMs closer in line that won't mess up WOT mixture?
How can I tell without a WB what effect any change may be having on WOT mixture?

I DON"T WANT TO CROSS 128 to the "DARK SIDE". (lean)

BTW: BLM is constant at 108 during idle.
Idles a 'little' rough (not much) and runs GREAT


Advice, opinions, guesses? ALL welcome.

Mods:

K&N and Open Lid
TB Bypass
AIRFOIL .... I know
ADS SuperChip

kevm14

Someone gave me an ADS chip once. I put it in and my BLMs were the same way. Extremely rich tune. Rich enough that the car had trouble starting.
Anyway...what makes you think that your WOT is perfect, but your part throttle is so rich? If I were you, I'd scale the entire VE table by 120/128 (or 120/125 like I do) and see how that works out. Your best bet, though, is going to be to fully tune your VE. It's not that hard with good software like WinALDL. Some folks like VEmaster, as well.

3.8TransAM

If its idle only, and i mean at idle only, u can move the 02 switching points as in tunercat. If that isnt an option for you the only thing u have left to do is start to modify the VE and/or timing tables(more timing =leaner , less timing richer).. Idle can be a lot of fun to tune (not lol)...

As a side note if your just beginning to burn proms check out traxs sticky on tuning and dig up some of the "final thoughts" posts and tuning tip articles, do some searching...

Also if u do plan on changing anything start out with a proven bin, aka. a stock chip setup and proceed from there with modifications
Later
Jeremy

VetNutJim

Hey guys thanks for the info.

I don't know for sure what the WOT BLMs are. They go to 128 and stay there during PE.

Anything less than PE and the BLMs show rich (108 to 120).

I don't want make changes to lean the BLMs and risk going lean during PE.

I have TC and DataMaster. I'm logging with DataMaster.
Also have Diacom and it's showing the same BLMs.

BTW, I'm FAR from being a tuner expert but I've read everything I can find on the net, several times. Have done a LOT of studying.

From a logical standpoint to not affect PE, the VE table seems to be the place to fix this.

I'd just like the input from you tuners out there for concurrence.

Morley

When you go open loop your BLM's are supposed to lock at 128, at this point they are meaningless. Since you are running a stock engine your best bet is to go back to a stock bin file.

kevm14

Ok,
1) Don't look at the BLM in PE. The ECM moves out of closed loop in PE (to richen below 14.7:1) and therefore doesn't look at the O2 sensor.

2) Adjusting VE WILL affect PE. VE is the most important place to look when calculating the final PW in PE or not.

3) That said, you are probably not lean in PE, and you probably won't be if you adjust your VE correctly. Move up your PE TPS engagement percentage and get some high load closed loop BLM values and begin to dial in your VE. As long as your injector constant is correct and you haven't specified a lean AFR for PE, your PE will likely not go lean as you adjust VE (by removing fuel, if necessary).

Grumpy

Tuning is about doing what the engine is telling you it wants.

If it looks rich in certain areas fix those specific areas.

When you start making universal changes, is when you can get into trouble. ie change the injector constant and you change the actual AFR compared to the commanded one at WOT. Then you can get into problems.

The advantage of EFI is being able to tune in very fine areas, rather then making sweeping changes. Might as well use the system 100%.

VetNutJim

I can adjust the lower VE table to fix this I believe.
I "could" adjust the VE for the ADS chip to the stock values. That would not be a problem.

PE I don't know about. I know they are locked at 128 that's why I indicated I had no idea what they were during PE.


Question:

What besides a WB or plug cuts can I use to adjust PE AFTER I fix the lower VE table?

Grumpy

Stop watch, GTech, and knock sensor.

Start rich and lean down as necessary. Of course watching knock sensor. Then working the timing back and forth, and the fuel, for the best combo. Least timing with min loss of performance.

VetNutJim

I checked my BIN files.
There's no difference in them until KPA reaches 90.

R665 is my original one.
AXCR was the next one I used
The ADS Superchip is in there right now.

There's just no difference in them until almost WOT.
That's way into PE.
They (ADS) are just adding a little fuel and 6 degrees of timing during PE. That's all the difference there is.

Therefore I don't think the calibration is causing this problem

Vette RUNS GREAT. Logged a 0-60mph run in 5.9 seconds a few nights ago.
Idles pretty good and has no rich odor.

I was just wondering. Could a old O2 sensor cause this?
Would low output from the 02 sensor cause BLMs to be low or high?

This one is probably the original O2 with 103,000 miles on it.

I picked up a new one on the way home this afternoon.
But I don't want to change it unless I really need to.

Grumpy and some of you other experienced tuners:

SHOULD I CHANGE TO THE NEW O2 BEFORE DOING ANYTHING ELSE?

kevm14

FYI, you can hit 80 or even 90kpa in closed loop with the stock TPS PE settings. It's going to be at a lower RPM, most likely, but you can probably do it.

VetNutJim

PE starts on mine from 400 to 2000 rpm at 50% TPS.
3200 rpm at 60.2% and 4800 at 70.3%

What about that 02 Sensor?

VetNutJim

Well.....here's what I did:

I reprogrammed the lower and upper VE tables.

Took my lowest reading.... (108) and my highest reading (120)
and averaged them (108+12)/2 = 114.

Divided 114 by 128 (114/128) = .890625. (rounded to .89)

Used that as a scaler for all the VE table number from 600 rpm on up.

The idle BLM is now 120 instead of 108 but becuse of rain, I haven't had a chance to do a data log run.

BTW: I cut and pasted the VE table values into a spreadsheet and applied my scaled value to the 'modified' rows.
(I stored the original VE values in the spreadsheet also so I can see at a glance what I started with)

Then I cut and pasted them back into the VE table.
Using a calculator and modifying them one at a time was taking toooooo long.

Any guesses on what the results will be when I get to drive it?

kevm14

You can use Excel to calculate the proper VE for any cell. Just export a text file from WinALDL from the BLM log. Then paste the average or narrow BLM table into Excel. I also copy the #samples table just so I can weed out cells that call for ridiculous changes with only 1 or 3 data points.

Next, I start 10 columns over, or so, in the same row as the first RPM of the BLM table. I enter the formula for that cell as

=B16/125

Where B16 is a cell containing a BLM from WinALDL and 125 is the BLM that I'd like to normalize to. Then I control-d and control-r to fill down and to the right in the size of the BLM table. That leaves me with all the correct ratios to scale my VE.

Then, I copy my current VE from TunerCat into Excel. Then all I have to do is multiply a ratio cell by a VE cell to arrive at the final, new VE value. You can make a new table in Excel for this.

VetNutJim

I guess I forgot to mention.

I'm using DataMaster for data collection.
I'm using TunerCat for BIN file modifications.

Still raining in Georgia... ....no test drive....yet.

The spreadsheet makes the whole thing a LOT easier.

Anybody else got any tuning tips, please?

kevm14

If you are using Datamaster, then export the data to Excel and make a pivot table. It should be MAP on the X axis and RPM on the Y axis and BLM as the data. It will make a huge table with every captured RPM and MAP combination with a BLM in each cell. You can specify to have Excel average multiple copies. Then you would pick off exact areas that match the cells on your VE tables, like 2000rpm and 50kpa, for example. It will be a lot harder to come up with a table of ratios to adjust each VE cell by, though. More manual labor is involved. That BLM table feature of WinALDL is priceless, imo.

Morley

Yes it is, and it sucks.