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Interested in OBDI tuning yourself?

G

great white

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Thread on another forum where the boys are working up to "open source" the ability to "tune" OBDI 6.5's:

http://www.gearhead-efi.com/Fuel-In...on-EC-Turbo-Diesel&highlight=6.5+turbo+diesel

I'm not involved with it, I ran across it in reference to another collaboration I'm involved with and thought I'd just put it out there for anyone interested.

They're just kicking off, so not a lot there yet.

But a good start.....
 
All my OBDI experience has been with gassers, but I'll guess a willem eprom programmer is required.

That's what I used to use before getting in to OBDII where you can just flash over the ALDL port.

My OBDI stuff has been sitting in a dusty box since I scrapped my TPI converted 88 ECLB K1500....
 
For the stock PROMs a UV drawer to erase them, an EPROM programmer and an adaptor to put them into the programmer.

Moates sells a progammer or there are others. Moates also sells EEPROMs that dont need UV drawer and they have the harness to adapt the chip to the pins of the PCM socket, and an adapter for the stock chip to the programmer.

Those xdf files posted are pretty crappy though, seen them before, all sorts of errors and just not well defined. This is why I made my own with the help of some disassembly from a couple programmers, including the guy that contributed for the posted thread. If someone were really serious about doing their own tweaking and has the hardware I can help them with stuff like fuel and timing, boost and tranny tables, probably send them a version of it, but Dale was pretty high speed already on his own, so imagine they already have a good start.
 
Those XDF files were built for a specific calibration ID, don't remember which one though. The different calibration ID's have a different XDF file that is slightly different. I've disassembled three different bins that I have and built files for them and they have different addresses for each table, scalar and dtc area. some of the stuff is the same but not enough to try and tune from. It's alot of work for someone to go through and label wrong, but you never know.
 
The errors I have found in the XDF files online are in the grid values, axis labels, poor naming conventions that most wouldn't understand, and missing some good stuff. Its not that someone intentionally labeled them wrong, just poor product from the original source. They are decent starting point, I just wouldn't trust them totally. I have a lot of the BINs and know the address variations.
 
How did you find out what to label everything if you don't mind. I found out through the stanadyne patent thanks to dale.
 
Mainly from disassembly from Dale and another person I worked with quite some time before that, some testing with the truck and monitoring scanner data, and some by DTC limits in the code and manuals and some sense, and reviewing other GM XDF files with the 4L80E helped some. I also noticed some of the equations are wrong, applying the wrong ALDL info to similar types of values. If you have another good source would love to know where to find it. I wrote my XDF file from scratch with all those inputs and eventually saw the ones available online, which did give me ideas where to go look in the disassemby. Are you EagleMark on GearHead-EFI? I was planning to register over there to discuss.
 
How much different are the older PCM's compared to the newer Duramax ones?
 
No I'm not Eagle-mark. I subscribe over there, cool site. Good people and good info on tuning. Not to many diesel guys over there ( well they don't speak up if they are ) I went about it the same way as you, but found the gas disassemblies only resemblences were the naming of tables and etc. Even the equations are different. But reading the ds-4 patent gave most of the naming along with dales disassembly. Most of the math is in the bin file already, below $4000 in memory, with reference pointers. I agree there is some equation errors in those XDF's, the one that sticks out the most was the App2, 3, just didn't jive with the data stream info when I built the ADX or XDF.



As for the difference from old to new PCM's, there is alot different, same principle. The duramax I believe is PowerPC programming while the 6.5's are motorola programming. Thats just the begining, don't know much about the duramax though.
 
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