I assumed the BLM #'s always stayed the same in the cells. I have hooked up the PC w/ winALDL today on 3 different ocassions and have 3 totally different readings. How can the cell stay at 128 constantly? I would think that is impossible. Burning chips sounds better by the minute. But could you ever get the tune juuuuust right?

This morning the BLM #'s averaged 121, this early evening, it averaged 108???

Any help greatly appreciated....BTW, is a code 33 not good for the engine. I'd figure a low manifold pressure would not be good, but high?

CHEVYTOWN L6 250cid moderatley modified. Howell universal kit.

 

It is possible to get them very close to 128 at all rpms and load ranges, but takes alot of tuning and tinkering. There is a program called VE Master for the $8D ecms that takes a recording from DataMaster scan tool software, and uses it to automatically adjust your VE tables, it works very good.
Rememer, the granularity of the VE tables is much finer than the BLM cells range of RPM and load, so thats why you can see the BLM#s fluctuating even though the same BLM cell is being read.
You only have 16 different BLM cells to divid up over all of the rpm and load combinations, so of those BLM cells, the engine can never reach, such as 100% load at 500 rpms, so your usable number of BLM cells is even less than 16.
Where as on the VE fueling tables in the prom, there are several hundred depending on the ecm.
For example, you have a BLM cell that is used for 1500-2000 rpms and 50-75% load, assuming you have a Speed Density and not MAF, which is a whole other ball of wax..you have 1 BLM cell for the above range, but in the VE table you have a separet cell for every 100 rpms, and for every 5 KPa's of intake pressure(load), thats makes 5*5 = 25 different VE values to control fuel.
So at 1500 rpms and 50% load, you could be rich and have a BLM of 108, but at 2000 rpm and 75% load you could be lean with a BLM of 138 after cruising at that rpm and load long enough, even though the BLM cell is the same cell as that used at 1500 rpms.
Adjustments can be made to the VE tables to average out the big swing in difference and make it close to 128 all the way across.
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Once the BLM's are close to 128, you can "lock" the BLM's to 128 in the chip, then use the INT value to further fine tune the VE tables manually in the chip, as the VEMaster program I mentioned ealier only uses the BLM readings.
All of this is given that your motor is a healthly good running with no physical problems motor.
Hope that helps.
And if you have a MAF instead of SD, I haven't figured it out for them on my other car yet as MAF does not have a VE table for fueling.

 

Thanks bro for your response. It's hard to get help around here unless you know what yer doin'. Although, I have met this one cool cat and he seems to be alright.

I'm not quite sure about most that you spoke of, but do understand some of it.

Is the VE number the one that should be 14.7 14/7...? Where can I find the VE tables?

I thought it was only the BLM #'s that were important, along with the sensor(s) data. Now I see how there is no way you can only use the prom burner/programmer just once.

The engine is a fresh rebuild. And these L6's will run forever man, I'm not kidding. So I don't see any problems with the powerplant.

I'm using WinALDL for a scanning tool. I have a universal kit from Howell, 560cfm 2bb, 87'-91' light trucks 305,350,454. It was pretty much plug and play. Although after reading about fine tuning the prom's/chips?, there is way more room for improvement. And according to the average 108 on the BLM cells, it is waaaay too rich. That makes sense as to why I'm at the pumps more than I'd like.

Is tunercat the same kinda program as VEmaster? That sounds like a kewl deal.

Thanks for your help again HOMETOWN...Ricardo

 

Tunercat allows you to edit the eprom data easily with a windows based screen interface. The VEMaster program is just a free program that someone on here created for the $8D ecms (90-92 TPI) that takes a data scan from the DataMaster scan tool and the eprom file definition as input, uses the 2 to create a new eprom definiton with altered VE tables. The VE table is volumetric efficiency tables that are used for fueling, the corresponding number in the table for a given rpms and load determine how much the injector pulse widths will be.
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For your 108 BLM reading, that is the lowest a BLM number can be usually, so your ecm is not able to correct the fuel any past that to lean it out for the rich condition. You really need to get them up, minimally to the 112-120 range so at least the ecm can do its job to control fuel. But if you learn to burn your own, 124-132 range is easily obtainable with a little time.
There are many good tech articles on this topic by Glenn and Traxion on how to do it. It takes alot of reading but once you take the time and make the investiment, you'll be so glad you did, its not very difficult at all. I finally started doing my own just a little over 6 months ago afetr I couldn't find anyone that was willing to try to burn one for my custom setup, and now I know why...if its not just a few bolt ons on a stock motor, there's not anyone who is going to burn you a chip that will make it run to its potential unless they spend lots of time, like days on end, and then that would cost too much.
If you already have a scan tool that records, then you got half the goods already, just another $200-$300 and you'll be on your way and be able to do so much more.

 

Kewl deal hometown. I have met Glenn and he invited me to another fulie forum just for L6's...He's the one who got me fired up in the first place, I was ready to learn from my new teach.....But haven't heard from him for some time now. It's kewl though, nowadays it's tough handle time, so little of it.....The information you have given me is a good start hometown, I'll do the searching....

Some cat by the name of funstick, has graciously stepped aside to help me go on the right path....Unfortunately, I just swapped in a 2004R that broke the bank. I'm not coming across any pesos anytime soon. I want to pay off the trans swap. But I hear ya bro, what a blast to be able to tell someone I AM the tuner!

I have read about tunercat/prom burner?...but get confused. Are both of these program files/folders stored on the hard drive? So then one is working off just 1 computer to handle the entire process?

My dumb/important question is for the next 3 months...will these low readings and the high manifold pressure, codes 45, 33...eventually destroy the engine?

Muchisimas Gracias amigo! CTOWN