OK, so you'd like to tune your TBI-equipped
B-body, but don't know how? Read on...
You need software to tune your ECM, unless
you already know the location and scaling/offset of each value in the calibration
file. Check out Tunercat -
you'll need to purchase the basic editor, and the ECM "definition file"
for the LO3/LO5 (which is the $62 calibration).
Now that you've got the editing software,
you'll need a way to "burn" chips (this ECM uses an EPROM, which needs
to be programmed out-of-vehicle in a special device). There's many
different EPROM programmers available; I'm currently using a BK Microsystems
device. You'll want something that supports a 2732 (4kbx8) 24-pin
DIP; this is supposed by most all programmers.
You also need a UV eraser, as EPROMs aren't
electronically erasable. You'll find them anywhere that sells EPROM
programmers.
The stock ECM looks like this:
With an EPROM carrier that looks like this:
In order to use a standard EPROM, the stock
EPROM socket must be removed and replaced with a standard
DIP or ZIF socket.
I used a 3M gold-plated ZIF socket (about
$10 from Digi-Key). It's a bit tricky to remove the stock
socket from the PCM, but soldering in the
new part is very simple. Once this is done, carefully cut the
plastic carrier from the stock EPROM so
that you can use it in your EPROM programmer (to read the
stock calibration file, or .bin) and the
newly socketed ECM.
This socket is kinda tall, so the stock access cover no longer fits snugly. This can be avoided by using a low-profile DIP socket, but this makes chip access a bit tougher and increases the chance of damaging pins during removal and install. The ZIF socket is really slick!
I'd recommend reading the stock .bin file from your stock chip, and then setting that part aside. Back up that stock .bin file, just in case! You'll need a supply of 2732 EPROMs, which are no longer produced. Either find them at an electronics surplus store, or hit eBay. The GM ECMs aren't picky about the specific speed or type of EPROM, as long as it's a 2732 of some sort.
Now that you can swap out EPROMs and you've got the software and hardware to do something with them, the real fun begins. As I gain proficiency with tuning the LO5, I'll keep updating this page.
Questions? Shoot me a message at eric@bryantperformance.com!