Just received my $58 def file and started poking around looking at some bins. I can't find a cylinder size anyplace. Doesn't the 749 need to know cylinder volume in order to calculate BPW? What am I missing here?

Confused????

Steve

 

I dont have it here in front of me, but I seem to think that it does have it. Yes it does have to know it for SD calculation. I seem to recall that it is the same as a 350, so I did not think twice about it, because that was the motor that I was going to run it on. I can check tonight when I get home if you dont find it sooner. the hack is on the GMECM site, that ought to have it.

BW

 

BW,

Thanks for the reply. I look again in TC and couldn't find it so I downloaded "Programmer 01" and it doesn't look like they have cylinder size either. I looked for the hack on GMECM but couldn't find $58. I found the 8D and some others. I'm sure I'm looking in the wrong place.

I was also surprised to see that the VE tables didn't go up into boost (above 100KPA). I've got lots of relearning to do on this one. Just getting started.

Thanks
Steve

 

The hac you are looking for is the "sunturd Turbo" hac.

I just checked through GMEPro & Terry does not have it in that either I find it hard to believe that it is not there, but there are 3 different editors & none of them have it. I was pretty sure that it was there, but obviously not.

Maybe they are doing something like messing with injector constants to come around from the back side to address the issue.

Maybe a post on the SyTy web site (or maybe GN) & see if any of them can shed some light on it. There is a guy on either GMECM or DIY EFI that wrote some SyTy stuff, I bet he would know. (I think that its the guy that wrote Promgrammer1), maybe an email to him. there are a few guys on the DIY site that have used it for V8 conversions.

Sorry I was not of more help.

BW

 

We Just Got done putting one on a L98...

Didnt tinker w/ Cylinder volume at all obviously, but then again going from 4.3 to 5.7 Is still the same bore/stroke so it shouldnt Matter.

Seems like you should be able to fudge around it anyway

 

Posted my Q's on the Syty forum and no one there could find cylinder size in the code? From reading the hack it looks like fueling is based on BPC (Base Pulse Constant) which is a combination of cylinder size and injector flow rate. Now I looked at a partially commented hack to find how the BPC is derived, but got way in over my head on assembly language mumbo jumbo. Apparently this is in F28A but the hack I was looking at diidn't have any details. So, I'll be relegated to fudging the injector constant number to get the VE table in the ballpark.

Received the Reman 749 ECM from GM parts Direct and the 2 bar sensor. Will repin this week and do a burn and try to bring this puppy to life!

Thanks to Saturn, Bort, Yenko, and all others who have already been here before me!

I'll have to post a pic of this thing. It's a riot.

Steve

 

The $58 code does not use the injector constant. There is no cylinder size term. As you discovered it is all BPC based. The $58 code is old and decrepit. It is actually a revised version of the early turbo Sunbird C3 ECM. Look at the code, it is nearly all GMCM based instructions. Hardly any P4 instructions to be found.

Also note that the gms/sec airflow calc does not work when the cylinder select is set for 8 cylinders. It always reports zero gms/sec airflow. At a minimum this affects the EGR calculations (hint: don't use EGR on an 8 cyl).

The fueling code is simplistic calculations, not even based on ideal gas law (as is the $8D). The code does not always follow the Turbo P4 document, there are differences.

Note that there is a boost multiplier term for the BPW calculations. It is a 2d table based on map.

Now that I've depressed most readers, at a minimum it still works better then F**d stuff. For an easy boosted solution it is mostly plug-n-play.

RBob.

 

Depressed? not at all. Seems then that put the $58 code in the same era as the GN code. The SyTy guys seem to be happy for the most part running $58 stuff, so tho its arcaic in design, guess it does the job.

There's the 8F code too. Has anyone done any work with it? I have done some lookng around but there doesn't seem to be much info thusfar regarding it. The bin size is 32K, all I have done is preuse thru it with WinBin. Used a 730 8D ecu file to open it so I am not sure if all the info is correct. Is there any benifit to running 8F over $58? From the lack of info I guess that it is not popular considering the work done with the $58 stuff. Hmm...just what I need.. another project..lol cheers, Bob

 

not trying to toot a horn but im working on a tdf based on the gpt hack. the code is mondo nicer however itll ned some work before primetime. also its a dis code but and i say but if you set the max advance and max retard the same as the $58 for a dizzy it should run fine. hint hint this is how you get a dis to work with $58 or so ive been told. the dwell calcs roll the dwell control backwards or foward based on rpm and ref pulse. im still sort of not clear on how it supposed to work but it does. ill get that $8f tdf up soon.

 

Thanks for the info!

What the heck are the 3.8L pontiac supercharged SSEI's running for an ECM? I'm sure they're probably Mass Air, but they must have provisions for boost retard and enrichment, as well as maybe a speed density backup system sorta like the LT1's

Neighbor is gonna repin tomorrow and I'l burn a chip when I get home from work! YeeHaa

Steve

 

I have a definition file for the $8F... it contains over 800 address areas, so it would never load in Tuner cat or Winbin.
The software I developed can accomodate definitions with thousands of address areas defined, so it works quite well for the larger 32k binaries. :-)
If you are interested, just let me know..

 

Ok, I'm gonna open myself up and show you'll just how dumb I am. What is DIS? I'm assuming it's a type of ignition. I haven't advanced past HEI and Optisparks yet.

The learning curve gets steeper the farther you go!

Thanks
Steve

 

Steve, try this for BPC calc:

BPC = 730.75 * (VOL / RATE)

; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec
;
; gms/sec = (lbs/hr / 3600) * 453.6
;

Should get you going.

RBob.

 

I think it was I getting depressed writing the above. An dyes the GN code is also on the old side. It is MAF & DIS though so it is a bit different.

The $58 code is smaller & better hacked then the $8F code. So it is easier to work with & tune. A benefit to running the $8F over the $58 would be for emissions and a more refined system.

RBob.

 

I beg to disagree. The $8F code has been just as thoughly defined as the $58, a task that was performed by me and a few friends.. :-)
The results were compliled into a definition file with over 800 address areas mapped out, which accounts for nearly every address in the data portion of the code.

 

Hey Mechanic, I'm interested. If you get a chance drop me an e-mail...
timsiford@adelphia.net

Tim

 

OK, can we see it?

RBob.

 

i dont want another editor. im hoping for a good hack.

 

Thanks very much RBob, That will definately help me back calculate my prorated injector constant. I am assuming that the SyTY 4.3 cylinder volume is hard coded. Anybody know what the stock SyTy injector flowrates were?

Well, we did get it fired last evening but it was butt ugly. It wouldn't idle. Seems way rich to me and misses like crazy, then pukes. We were not throwing any code at all which is almost unbelieveable to me. I started with Saturn's bin and we went way up on injector constant and way down on injector constant and seemed to get the same results. I'm using a 27c256 Eprom and a remanufactured 749 ECM from GM parts direct. TPS voltage is about .70V at closed throttle.

Thought that I found my problem when I read the bin file off of the chip and found that my load started at hex 0000 instead of 0400. So I reburnt a chip that was blank from 0000 thu 03FF and had the code from 0400 thru 7FFF. We had SES lignts blinking and a huge mess with that burn. Why again are we supposed to start at 0400?

I was using freescan but it doesn't give a lot of IO bit information so I might have to invest in Datamaster for better visability.

Thanks
Steve

 

Not sure which bin of mine you are using. Post some specs, and I can attach my current bin. cheers, Bob

 

Should be $4000 (check # zero's). Please go back & check my first post to this thread. The tps @ .7 is a tad high should be lowered a bit (to ~.54v).

What part of PA is Gardner at?

RBob.

 

Rbob,

My post was incorrect. I was starting the load at $4000 not $0400. I'm not very terrific on the keyboard and fat finger lots of stuff. Does the front of the 256 chip have to be filled with anything or just left blank? We'll work on the TPS a bit but I can't imagine that were far enough off to be running this ugly. I took off work today to dork with this thing and see if we can make any progress.

BTW - Gardners PA is just south of Carlisle PA and North of Gettysburg PA. Do you live nearby??

Bye

 

I zipped up a set of 32K bins for you. Both are current from my malibu. One is set for automatic, E2A32K.bin the other is set for manual trans. E2M32K.bin. Both are set for 30lb injectors. There is a text file included listing changes to each. cheers, Bob

 

The SES light flickering is indicative of a bad PROM, What Program are you using to Edit with ?

I had this problem with Promgrammer Because it fails to automatically Update the Checksum.

Stock Sy/ty uses 30 lbs injectors.

Fill the first half of the PROM with FF, empty.

Burn your Bin to the second half, or Do like Bob Says and double the bins up.

Starting at $4000 accomplishes the same thing.


Good luck, Anxious to hear how this works out. When you get it all said and done, Would you mind contributing a bit to my Webpage Since your application is a bit more one-off than the simple L98 install we did ? Be Nice to get some info on a Non TPI use of the ECM.


http://www.speedtoys.com/~bort62/7749/Main.htm

 

As the day draws closed I hope you have some good news. I am located about a 3rd of the way between Philly and you.

On the '749/'730/'727 with a '256kb prom running mask $58 the actual bin should start at the middle of the prom. Hence the $4000 starting address. Bob also showed another way to do it which is to double load the bin. In both the lower & upper halves of the eprom.

A cksum error will cause a rapidly flashing SES light. A missing bin should cause a solid SES light along with running off of the limp mode NETRES. A solid SES may also be caused by a bad sensor, to which a default value will be substituted.

RBob.

 

not that anyone cares but im working on the $8f tdf i got some more info from my guardian angel and got some help fixing things wrong with the hack. peace out. anybody got a way to help out ?

 

Did a lot of experimenting today with multiple burns, swapped a 730 ECM in, Injector constants at each end of the spectrum,etc. Still garbage. Here's the strange thing. If my burns start the $58 code a $0000 and run up to $4000 I get good communications with Datamaster, Good TPS,IAT,MAP, Clnt Temp Etc. I get no SES light and throw no codes. Motor runs like crap but other than that, life is good.

Now

If I burn starting at $4000 and fill the front half with 00 or FF, The result is all bad. Not able to sync with Datamaster, SES all over the place, big problems. I gotta be missing something stupid here.

Im gonna recheck wiring and go back to square one. Lets see

Swap injector ground
Swap IAC coil wires
V8 Memcal
Base bin
27c256 Eprom

Oh BTW it got identical results running 58 code in a 730 as I did the remanufactured 749. Woooo Hooo YiiiPeee

I have a pic but the BB says its to big to attach so I'll work on paring it down

Thanks
Steve