Need Help Tuning 3400 J-body swap

[SScavy]

Hopefully someone on this web site will be willing to lend a hand. I currently have requests on 3 other sites.

I recently purchased a mcumall burner along with aldl connectors, gmpcm, tunerpro r/t, and a few other things.

I've been fighting with this thing for 2 weeks now. I can burn an at29c, but they never work right and throw codes on me.

What i'm trying to do is program this at29c memcal to operate my new 21 lb/hr. injectors properly. I'd also like to remove my speed limiter, and bump my rev limiter to 6300 rpm's. Eventually understand BLM's and how to set those right, and get this baby running ideal for performance. A hair on the lean side.

Is there anyone out there willing to lend some knowledge. I've tried reading countless web pages and other web sites forums on tuning and can barely comprehend what they're trying to say. Everything they're talking about is over my knowledge so far on tuning.

Please help.

Thanks

Mike

[Mars]

Tune the BPC vs. desired EGR table till the BLM's are 128 give or take 2 -3. Do this at 0% EGR, and turn the EGR off but setting it's turn on temp to something really high. You can turn it back on later, after this step is done.

The rev limiter, if you're not bouncing off the stock one, leave it stock, other than that, advance it in small increments, and make sure you're going the right wat with it, some of the tunning software out there is ass-backwards.

Good luck.

[burn]

make very small increments when you tune the BPCvsEGR. check your datalog that your BLMs are below 128 (id assume so) a decrease of 0.001 can shift your BLM count by like 2-3.

[SappySE107]

I dont tune the BPC table that way but it probably works. There is a calculation to set the table for the injectors so the computer knows exactly what increments of fuel it really has.

EGR off is the easiest way to set this but once you turn the EGR on, you gotta do the math for each %...so just leave it off and don't worry about it till much much later.

Ok, here is the math. Good luck.

Base Pulse Constant vs Desired EGR Constant = 1461.5 * (EGR Factor)(Liters/Cyl)/(injector rate). Injector rate is gm per sec.

When I was using 21.9# injectors (ford 19# but at the GM fuel pressure), I used 177 as my constant for 0% EGR. I knew how to do the math at one point in time but have since forgotten it. Id guess 182 or so should be close for 21# but at least you have a starting point.

Tuning the 3400 using 3.1 code is not how I recommend learning.. I spent 6 months learning on a modded 3.1 (cam, port work, larger TB, larger injectors). I still have to get the 3400 fiero setup I was working on last year so I can finish up my own code for the 3400 chips. Trust me, if it was simple I would have had it done by now.

You will have to understand BLM and INT to have a chance at all. BLM is your long term fuel, INT is short term. What you need to do is set your BPC vs EGR first, then tune idle. Get the car warmed up so the O2 sensor is functioning properly. Then, let it idle till the INT is at 128 (unless BLM is at 100 or 156...then it will never have 128 INT. 128 is your target for both. What I do for idle is record the values, add BLM and INT and divide by 2. Then take that number and divide by 128. Then take that % and select the entire idle fuel table and either increase or decrease it by that %. Its not going to be dead on your first try for getting idle at 128/128 but it will be decently close. Just keep changing the idle table till idle is damn near 128 BLM. The way the INT and BLM work is simple. INT moves fast and the BLM will move based on what the INT is doing. So if you are lean, the INT will go 128 129 130 131 etc. Then, if the INT is above 128 for a little while, BLM will go 128 129 130. Now say you are rich, BLM is say 140, caught up to the INT that has now moved to 128 (int at 128 keeps the BLM at 140), but the INT is now saying we are rich, and goes 127 126 125 etc. BLM will go 140 139 138 etc slowly.

Now apply this to cells. Cells are broken down by 0,1,2. 0 is idle. 1 is normal driving, cruise, acceleration. 2 is decel. So tuning idle takes care of the 0 cell. While driving, you will hit 1 and 2. In cell 1, you could have 140 BLM and in cell 2 it will immediately jump to 107. Just an example. Just make sure you understand why it jumped like that.

Good luck. Specific questions will get you more responses because this is seriously a ton of stuff to learn and its overwhelming for me to even contemplate writing up a guide to fulfill everything. Upload a datalog and a .bin file (i dunno if you can upload those things here or not, haven't tried). It would be easier to make the changes for you and then explain the changes. Some things would require me to have the car though to know how its driving. Can't say id do that for free but ill try to help you learn it as best I can.