Programming PROMs for your Thirdgen Fuel Injected F-Body: Part
I Introduction
By Tim Siford, aka Traxion ( trax@frederickmd.com )
Warning: The information presented
below is presented for educational purposes only. Use this information
at your own risk. Be aware of your emissions laws and be aware
that changes to the car's stock computer chip can cause your car
to no longer be compliant with State and Federal emissions guidelines.
Furthermore, be aware that changes to a car's stock computer chip
can have very serious detrimental consequences to both your car
and those individuals in the car as well as innocent bystanders
outside the car.
OK, with that said, let's get right to it. You want
to program your own chips right? Maybe you're sick of paying ridiculous
prices for a 'custom' computer chip. Maybe you're sick of having
to depend on someone else to get your calibration right. Or, maybe
you're just determined to do it yourself. Well, you've come to the
right place. Many sites on the Internet go directly into what a PROM
is and give you all sorts of technical information that can be very
useful once you understand the basics. But, the fledgling thirdgen
PROM programmer isn't really concerned with this information. Most
of us performance oriented '85-'92 F-Body aficionados already know
that there is a computer chip in our car that has certain calibrations
for spark, fuel, etc. What we really want to know about custom programming
chips is...
What will I need?
How do I do it?
And... How difficult is it?
What you need...
- You need a computer. No big deal there because if you are reading
this then you have a computer.
-
-
You need a piece of equipment that can read and
program PROMs. This is most often called a 'Programmer'. This
piece of equipment will be utilized to read and program your
PROMs. The Programmer connects to your computer through the computer's
communication port (COM or Parallel port). When you buy the Programmer
it will come with software that communicates with the Programmer.
This software is installed on the computer to which the Programmer
is attached and it is used to control the Programmer (for reading
from and writing to the PROM). Reading PROMs will produce an
image of your PROM stored in a file with a .BIN extension (binary).
It is this binary file that must be modified in order to change
things such as fuel and spark parameters. The binary file is
often called a BIN. I use a Programmer called the 'Pocket Programmer'
that is made by a company called Xtronics. It is reliable, easy
to use, and economically priced. It is also an external unit
(you don't have to install it inside your computer). This means
that I can take it with me if I need to custom program a chip
away from home (like at the local dragstrip!).
Pocket
Programmer
Source: Xtronics
PN: I-PP2
Price: $150.00
http://www.xtronics.com/memory/EPROM.htm
Be aware that there are many other types of Programmers
on the market. Two of the more popular Programmers can be found
at the following Internet sites...
http://www.arlabs.com/
http://www.needhams.com/
-
You will need ANOTHER special program to read
this BIN and allow you to modify it. This 'other' program (also
known by the word 'Editor') is not supplied by the company that
makes the Programmer. It is not supplied with your Programmer.
I use an editor called 'TunerCat'. TunerCat is available at
http://www.tunercat.com.
However, there are several other programs available on the Internet
that you can use. A couple of the most popular ones are:
ALL of these editors have special calibration files (also known
as definition files) that you load into the program before opening
your BIN. This calibration file tells the editor exactly how
to read your BIN. The BIN needs to be interpreted appropriately
and the 'calibration' file takes care of this. This is extremely
important because not all EPROM images are organized in the same
manner. A good example of this would be comparing a 1989 IROC-Z
to a 1990 IROC-Z. The 1989 IROC-Z uses a Mass AirFlow Sensor
(MAF) in order to directly measure the amount of air entering
the engine in order to supply the appropriate amount of fuel.
However, a 1990 IROC-Z, which uses Speed Density engine management,
does not have a MAF and does not directly measure the amount
of air entering the engine. Thus, you would expect that these
cars would have different code in their EPROMs. Well, in fact,
they do. Thus, the editor needs to know where to find the appropriate
information inside of the BIN. This is accomplished by loading
the calibration file into the editor before loading the BIN.
In reality, each ECM (Electronic Control Module) has a specific
type of EPROM and a specific organization of the code contained
in that EPROM. EPROM type and EPROM organization can change from
one year to the next so it is important to know what type of
EPROM you have in your car and the common term for the EPROM
organization (also known as the 'Mask'). See the table at the
end of this tech article to view the information for your F-Body.
-
Spare EPROMs. It's much easier to just pull your
existing chip out of the ECM and then slap in the new one with
the updated calibration instead of constantly reprogramming the
same one. The only way to do this is to have spare EPROMs. You
can order EPROMs from various sources on the Internet. But, you
need to be aware of the specific EPROM type that your F-Body's
ECM needs. As noted in Item 3 above, the EPROM type is specific
to the year of your F-Body and engine type (TPI, TBI, etc.).
When shopping for EPROMs you will notice that they are available
in many different speeds very much like memory for your home
PC. Most custom programmers have noted that you can use any speed
of chip available. This is great because the slower EPROMs (250ns)
are cheaper than the faster EPROMs (50ns) and they work just
as well. Moreover, some EPROMs are labeled as OTP EPROMs. OTP
stands for One Time Programmable. Do not buy these PROMs because
they can not erased.
There are various sources for EPROMs. I have noted
a few below...
http://www.digikey.com/
http://www.jdr.com/interact/default.asp
http://www.jameco.com/
http://www.pios.com/
EXAMPLE: 1990-1992 TPI F-Bodies (305 and 350)
require a '27C256' EPROM. See the table presented at the end
of this tech article to determine the type of EPROM needed for
your car. For EPROMs, I am using the following for my 1990 IROC
350:
28-pin, 256K CMOS EPROM (32K x 8), 90ns, CERDIP
Source: JDR Microdevices
PN: 27C256-90
Price: $3.99 http://www.jdr.com/interact/default.asp
-
If you are using EPROMs (and not EEPROMs - see
the important note below) you will need an EPROM eraser
. You need to erase the EPROM before you program it. Exposing
EPROMs to UV light erases them. Thus, an EPROM eraser is a
piece of equipment that has a UV light bulb (that shines at
a particular wavelength) and a place to put the EPROMs so that
they are exposed to the UV light in the device. Every EPROM
(except OTPs, One-Time Programmables) will have a small quartz
window on its top surface. This quartz window gives visual
access to the true hardware that stores the information (basically
0's and 1's). On stock GM EPROMs this quartz window is covered
with a small silver sticker that has the GM part number on
it. Removing this small sticker will reveal the quartz window
that yields visual access to the memory module. This small
sticker prevents UV light from entering the EPROM. This is
important because you do not want sunlight to begin to erase
the EPROM. Now, in theory, it takes a couple of weeks in the
sun to erase the entire EPROM. However, several custom programmers
have noted that their EPROMs were fully erased in only 2 days
in direct sunlight! So, be careful. Always cover the quartz
window before programming your EPROM. If you don't have a sticker
to cover the EPROM window or if your GM sticker loses its stickiness
then use electrical tape. Electrical tape can withstand the
heat that the EPROM will most likely experience. Regarding
EPROM erasers I use a DataRase II which is very common among
EPROM programmers. Never look
at the UV light bulb or expose your skin to it! It is dangerous
to your eyes and skin. It could cause permanent damage!
DataRase II EPROM eraser
Source: DigiKey
PN: ER2-ND
Price: $39.95
http://www.digikey.com/
IMPORTANT NOTE: The 'rage' among
us chip programmers is the use of flash proms (called EEPROMs
for Electronically Eraseable Programmable Read Only Memory).
EEPROMs make our lives much easier in that a UV Eraser becomes
obsolete. To program an EEPROM you simply put the chip in the
programmer and program it. The programmer will both erase the
chip and reprogram it. This is wonderful. There is no need for
a UV Eraser, no need to wait for chips to erase, and the chips
have a much longer burning life since they aren't being pounded
by UV light! The magic part number here is AT29C256. It is a
32Kb chip manufactured by Atmel. This chip is a direct replacement
for all 27C256 chips used in 1990-1992 TPI F-Bodies (32Kb). This
does NOT mean that it cannot be used in previous year TPI vehicles.
You just need to do a little 'tweaking' during the programming
process. 1986-1989 TPI F-Bodies use a 27C128 chip of 16Kb. The
Atmel AT29C256 chip has twice as much memory. To make these chips
work on 1986-1989 TPI F-Bodies you can do one of two things:
either make sure you program the BIN into the last 16Kb of the
32Kb EEPROM (using options on your programmer) or just double
the BIN using DOS commands and then program the EEPROM. For the
DOS method just take the BIN you wish to program and name it
test1.bin. Copy it. Rename the copy test2.bin. Finally, go to
a DOS prompt and type "copy /b test1.bin+test2.bin test.bin" (without
the quotes). You now have a doubled BIN called test.bin that
you can program the AT29C256.
That's it! That's all you need. You can purchase
reliable equipment for items 2-5 for around $200 (not including
the Editor). Yes, you heard correct. For $200 you can be burning
your chips! When using EEPROMs the cost is substantially less
than $200! But, it will take a lot of background information,
a lot of testing and experimenting, and a lot of experience before
you become talented at doing it.
How you do it...
- Hook up your newly acquired Programmer to your computer as
per the Programmer's instructions.
- Load the Programmer's software, Run the software, and choose
the correct EPROM type.
- * Pull your computer chip from your car and put it in the
Programmer in the correct manner.
- Use the Programmer's software to read your chip.
- Save the chip image to your hard drive. This is the BIN.
- Remove your computer chip from the Programmer and shutdown
the Programmer's software.
- Run your Editor.
- Load the correct calibration file.
- Load your BIN.
- ** View/Change the chip's parameters and tables.
- Save the new BIN.
- Shutdown the Editor and run the Programmer's software.
- Ensure the correct EPROM type is selected.
- Place an erased chip on the Programmer.
- Do a 'blank check' to ensure the EPROM is erased.
- Program the EPROM with the BIN saved in step 11 and then
verify the program.
Simply put, that is how you program EPROMs for 1985-1992 F-Bodies.
Steps 1-9 and 11-16 are the easy steps.
Step 3 marked with '*' may require more work on your
part because the EPROM in all TPI equipped 1986-1992 F-Bodies is
physically attached to a carrier. This carrier is a bigger plug-in
module that inserts into your ECM. Most inexperienced F-Body enthusiasts
mistakenly call this the 'chip'. However, for '86-'92 TPI F-Bodies
it is more than a 'chip'. Technically speaking, this carrier is called
a MemCal. MemCals are easily recognized by their bright blue protective
cover. Underneath the blue cover, the MemCal will contain the bare
EPROM along with the limp home mode chips (netres, short for network
resistors) and possibly the ESC Filter ('90-'92 TPI F-Bodies, aka
Knock Module). Thus, it is not as simple as pulling the chip out
of your car and putting it directly into the Programmer if you have
a '86-'92 TPI F-Body. If you have a TBI equipped F-Body then you
do not need to worry about this because the EPROM plugs directly
into the ECM; there is no MemCal. For you '86-'92 TPI owners, there
are 3 ways around this. Each method is mentioned below along with
pictures. A more detailed explanation of each method follows.
- Desolder the EPROM from the carrier and then solder a Zero
Insertion Force (ZIF) Socket in its place so that you can take
the chip on and off at will. Here are some pictures that document
this method:
-
Stock
GM MemCal
Stock
GM MemCal with protective cover removed.
Low-Profile
ZIF
Modified
GM MemCal with ZIF
Modified
GM MemCal with ZIF and new EPROM
-
Make an adapter to burn the PROM while it is
still in the MemCal. This is the method similar to what the big
chip people use (i.e. TPIS, AS&M, etc). Here are some pictures
that document this method:
Adapter
in its modified and original form
Adapter
in the Pocket Programmer #1
Adapter
in the Pocket Programmer #2
MemCal
attached to Adapter in Pocket Programmer
-
Method 3 is the most popular method and is, in
this author's opinion, the best way. Obtain a used HyperTech,
ADS, or Jet 'chip' adapter or purchase the adapter from
Craig
Moates (please see
Craig's
MemCal adapter page for more information). This makes things
very easy because it comes with a chip socket that is already
heavily soldered to a thick computer board. With the HyperTech,
ADS, or JET adapters you just pry out the existing EPROM and
put in your own. Your existing MemCal piggybacks onto the adapter
so that the limp home chips and ESC Filter ('90+ TPI) are still
used. Easy. Here are some pictures that document this method...
MemCal
Adapter
MemCal
Adapter with EPROM
MemCal
Adapter with EPROM and MemCal
Craig Moates' adapter is very nice because it
comes with a ZIF and, therefore, makes the chip exchange very
easy with the absolute least wear and tear on the ECM's or MemCal's
socket. Please keep in mind that everytime you remove the MemCal
or the adapter from the ECM you are putting wear and tear on
the socket! Using a Craig Moates' adapter or something similar
will prevent this because you can simply leave the adapter in
the ECM and use the advantages of a ZIF by just removing the
chip from the ZIF. Now, if you do manage to find a used HyperTech,
Jet or ADS adapter really cheap don't pass up on it! I have successfully
installed the low-profile ZIF mentioned in step 1 into one of
these adapters by simply pressing it into the open socket and
using some hot glue to secure it for peace of mind. This is what
I have been using and it works like a charm. Please note that
if you utilize method 3 then you will not be able to reattach
the cover plate for the ECM. This, however, is not a big deal.
Once you get the BIN worked out simply follow method 2, install
the MemCal and cover plate, and put the ECM back into the dash.
Some people even purchase an extra AT29C256 and solder it into
the actual MemCal in place of the stock 27C256 or 27C128 to make
using method 2 that much easier.
Option #1 Explained: When using option
1 I used the following parts to construct the ZIF MemCal...
Socket
28PIN ZIF Lo Profile
Source: Digi-Key
PN: A347-ND
Price: $6.50
http://www.digikey.com/
Soldering
Iron Tip .015 Conical
Source: Digi-Key
PN: K342-ND
Price: $7.95
http://www.digikey.com/
Soldering off the existing EPROM can be tricky. But,
it is not that difficult. You will want to make sure that you utilize
a solder iron with a very fine tip (which is why I have listed a
part number and description for one above). Big and/or thick tips
will not work. You will want to gently pry up on the EPROM with a
jeweler's screwdriver as you desolder the legs one at a time. It
is a slow and crude process, but it works beautifully. Be patient.
Some individuals have found that using a 'solder wick' helps ease
this process. A solder wick sucks up liquid solder so that you can
remove it easily. In any case, once the EPROM has been removed from
the MemCal simply solder in the ZIF socket. CHECK FOR CONTINUITY
using a Digital Voltmeter (DVM). This is of utmost importance. You
want to make sure that each pin on your ZIF really is connected!
Finally, use a hot glue gun to firmly attach the ZIF to the carrier.
The solder holding the legs of the ZIF to the carrier is strong,
but not that strong. It is relatively easy to break a leg free from
the ZIF / MemCal connection. Using hot glue ensures that the ZIF
is firmly in place and will stand up to your many removals and insertions
of EPROMs. If you utilize this method then you will have to remove
one of the MemCal retaining clips in the ECM because it contacts
the ZIF.
Option #2 Explained: When using option
2 I used the following parts to construct the adapter...
34-Pin
Wire-wrap protected header
Source: Digi-Key
PN: CHW34G-ND
Price: $4.46
http://www.digikey.com/
Use a dremel and cut off as many pins as necessary
in order to leave 2 rows of 14 pins (total of 28 pins). Using the
34-pin header mentioned above, I had to cut off a total of 6 pins
(or, 2 rows of 3 pins). What you are trying to achieve is to make
sure that all legs extending from the EPROM soldered to the MemCal
join to a pin on the adapter you are making. Since the EPROMs have
28 legs (14 legs on each side), you need an adapter that has 28 pins
with 14 pins on each side. Cut off any and all other pins. I also
removed the sides of the header in order to make the adapter easier
to use. Once you have cut off the necessary pins you will need to
bend each row of pins slightly outward in order to be able to fit
the adapter into the Programmer. The pictures previously presented
provide a reference for this.
When utilizing this option and NOT using AT29C256
chips (which I highly recommend if you decide to
use this method!) I have been asked many times how I erase the EPROM
if it is still attached to the MemCal. The main reason that this
question comes up is because the entire MemCal will not physically
fit into the EPROM eraser. Also, there is usually a low tech safety
mechanism on EPROM erasers that prevent the UV light bulb from shining
unless the door on the eraser is closed. The door cannot be closed
when placing a MemCal into the eraser. Normally, this is great. But,
it can be frustrating when trying to erase an EPROM that is still
in the MemCal. However, since EPROM erasers usually employ a low
tech defeat mechanism (especially the Datarase), it is relatively
easy to bypass once you work with the unit. However, please follow
the warning previously outlined. Click
here for a picture of the MemCal in the DataRase. Do
not look at the UV light bulb! Do not expose your skin to it either! I
usually place the DataRase in an 'abandoned' room. I close my eyes,
turn on the unit, run out, and shut the door upon leaving (to ensure
no pets or children wander into the room). I come back 15 minutes
later. My unit has an automatic shutoff so when I return the UV light
has already been turned off. Another method that has been suggested
is to cut a hole in the cover of the unit just big enough to slip
the MemCal into the chamber. This method is nice because it allows
the original cover to engage the safety mechanism and because it
keeps most of the harmful UV light inside the unit. However, you
will have to be willing to cut a hole in the sliding cover. Remember,
if you decide to use the AT29C256 chip then you will not need to
worry about the UV eraser and the hazards of this step because the
programmer will automatically erase the chip before it programs it.
Again, this author highly recommends the use of AT29C256 chips if
you decide you wish to pursue this method.
Another popular question is whether the UV light will
hurt/destroy the limp home mode chips and/or the ESC filter on the
MemCal. The answer is no. UV light will not harm these components
of the MemCal.
Also, for your information, the current GM (AC Delco)
part number for a new MemCal unit for all 1990-1992 350 F-Bodies
is 16151348.
Step 10 marked with '**' is the step that requires
a lot of learning on your part. You will need to become familiar
with the editor that you are using. You will need to become familiar
with what that editor gives you access to inside of the BIN. You
will need to learn the acceptable changes for the various parameters
and tables in the BIN. You'll need to research and/or learn how and
what to change for various engine changes. You'll need to research
and/or learn how and what to change for various drivability problems.
Pay important attention to the 2 sections of this article entitled:
'Important Information for Beginners' and 'Modifying the BIN'. These
sections will give you a head start on this task.
How difficult is it?
Let me break it down again:
Pull the chip from the ECM.
Read the chip using the programmer.
Save the BIN.
Open the 'other' software.
Load the BIN along with the calibration file.
Make the necessary changes and save the new BIN.
Load the programmer's software and load the new BIN.
Put a blank chip on the burner and program it.
That's it.
It is not difficult nor time consuming to program
new chips. But, you must do the research and you must invest time
to learn. You can program a new EPROM in a matter of a couple of
minutes. But, the research in learning how and what to modify in
the BIN can be extremely time consuming (and at times frustrating).
On the other hand, the rewards are nothing short of spectacular.
The next section covers this issue in more detail.
Important information
for beginners
Presented below are several references that will give
you a jump-start on changing a BIN's parameters and tables. Read
through these links ... then read through them again.
Internet Links
Grumpy's tuning tips: http://www.diy-efi.org/diy_efi/oem/gm/tunetip.html
Grumpy's Programming 101: http://www.diy-efi.org/gmecm/papers/prog_101.html
GMECM FAQ: http://www.diy-efi.org/gmecm/faq/
GMECM: http://www.diy-efi.org/gmecm/
Thirdgen.org PROM Forum: http://www.thirdgen.org/techbb2/forumdisplay.php?forumid=16
TRAXION's Tuning VE Curves: http://www.thirdgen.org/techbb2/showthread.php?s=&threadid=39254
Michael Davis' Page: http://www.eecis.udel.edu/~davis/z28/
Ludis' Page: http://www.cruzers.com/~ludis/
ECMGuy's Page: http://www.geocities.com/ecmguy.geo/
Mr. Gasket's EFI Tuning PDF: http://www.mrgasket.com/ftp/pdf/EMIC.pdf
LJ's LT1 Page: http://para.noid.org/~lj/PCM%20Tutorial/PCMtutorial.htm
Helpful Books
- Jeff Hartman,"Fuel injection - Installation, Performance tuning,
Modifications", Publisher Motorbooks international.
- Watson, Ben, "How to Repair and Modify Chevrolet Fuel Injection",
Motorbooks International.
Mailing Lists
A very good source of information besides what I have presented above
can be found by joining mailing lists. The most informative is the
GMECM mailing list located at http://www.diy-efi.org/subscribe.html.
There are many members of this mailing list who have years of experience
burning chips for ALL types of automobiles. You can learn a lot from
them. There is also a mailing list for TunerCat located at http://www.topica.com/lists/TunerCAT.
Modifying the BIN
Inevitably, once an individual understands this article
and understands how to use all of their new PROM equipment, the following
type of question is posted to the PROM message board or the GMECM
mailing list...
Question: What do I modify in the
BIN for my F-Body 1991 350 TPI that has 24lb injectors, 58mm TB,
TPIS MiniRam intake, AFR195cc heads, LPE 219/219 camshaft, SLP 1-3/4" headers,
catback exhaust, 180º thermostat, 4.10 gears, 2400 stall converter,
and a shift kit!?!!???
Answer: If only it were that simple.
In my experience a newbie PROM programmer wants to
immediately jump in and make the 'perfect' chip for
their setup. But, it is not that easy ... not even
close. This new chip may take you months to get correct.
Although you can program a new PROM in a matter of
a couple of minutes, it takes significantly longer
to develop that BIN so that it will work with your
new setup. Again we arrive at my previous comments
in the 'How you do it...' section of this article.
The process of modifying a BIN to work perfectly with
your car requires research, experimentation, time,
and patience. You will probably burn 10-200 chips to
get your calibration correct depending on how radically
different your new setup is from your old setup and
depending on how much you know. Again we see research,
experimentation, time, and patience (where research
and experimentation are the ultimate keys!). The more
you learn the quicker you become at developing the
correct BIN. The more you learn the more doors that
are opened. Begin your research by going through all
of the links in this article several times. You'll
also want to read the previous posts on the PROM message
board. Finally, the GMECM mailing list is the ultimate
mailing list for these topics and there are archives
that go back years. The archives alone act as
a library to answer almost every question imaginable.
The archives are located at ftp://ftp.diy-efi.org/incoming/ and
are entitled 'GM_ECMArchives.zip' and 'DIY_EFIArchives.zip'.
With all that said, let me break down the original
question into a couple of other questions that
you should be asking yourself...
- I am using 24lb injectors. What do I modify in the BIN to compensate
for larger injectors?
- How does a bigger camshaft affect the fuel curve?
- I need the ECM to turn the fans on sooner due to my use of
a 180º thermostat. What do I modify in the BIN to do that? Are
there any other considerations of running a 180º thermostat?
- What am I seeing via a scan tool? Any knock retard? What are
the BLMs at various conditions?
- Modifying the air intake of the stock TPI to a MiniRam and
58mm TB will have what affect on the airflow characteristics
of the engine?
- What do my spark plugs look like?
Some of these questions apply directly to how you
modify the BIN. Others questions are theoretical questions that relate
to general engine theory. Other questions are reality questions that
determine exactly how your engine is running at this point in time.
In order to program PROMs successfully you will need a general understanding
of engine theory and you will need a way to determine how your engine
is currently running. These yield a great foundation from which you
can learn more when conducting your research and doing your experimentation.
My recommendations for a new PROM programmer (who
is already in the process of conducting all of their research) is
to begin very slow. This means beginning with the easy stuff.
Most BINs can be broken down into 3 elements that the tuner (that's
you!) has available to them. Later on in life you will find that
there are more than 3, but, for right now, we'll say there are three
main elements: flags, constants, and tables.
Flags are switches. They have only two working values
(like a light switch: ON and OFF). Flags are things like...
- Enabling/Disabling Functions (VATS, etc)
- Enabling/Disabling Diagnostics (EGR, VSS, etc)
- Switching between one element and another (Auto or Manual transmission?,
etc)
Constants are single values. Constants are things
like...
- Fuel Cutoff speed (mph)
- Fuel Injector flow constant (lb/hr)
- MPH for Torque Converter lockup
- Fan On/Off Temperatures (deg. C)
Tables are groups of values in relation to other variables.
There are two-dimensional tables (2D) and three-dimensional tables
(3D). Examples of BIN Tables are...
- Pump Shot vs. Differential TPS (2D Table)
- Target Idle RPM vs. Coolant Temperature (2D Table)
- Main Spark Advance vs. RPM vs. Load (3D Table)
- Volumetric Efficiency vs. RPM vs. MAP (3D Table)
In my opinion, the order of difficulty in terms of
modifying the BIN is: flags, constants, 2D tables, and 3D tables.
I previously stated to begin slow. Well, if possible, begin
your experimentation with the flags, move on to constants, then 2D
tables. Finally, work on the 3D tables. This is a good approach because
it gets you accustomed to the overall procedure of modifying a BIN
which is to research the changes, make the changes, burn the PROM,
and evaluate changes. It also gets you accustomed to working with
your new software, your new equipment, and your automobile.
Lets now examine the 'radical combination' previously
suggested (1991 F-Body 350 TPI that has 24lb injectors, 58mm TB,
TPIS MiniRam intake, AFR195cc heads, LPE 219/219 camshaft, SLP 1-3/4" headers,
catback exhaust, 180º thermostat, etc)...
The car is equipped with a TPIS MiniRam which does not
have EGR. Most likely the owner is experiencing a check engine
light that yields a code pointing to the EGR not functioning properly.
I would suggest beginning with disabling the EGR diagnostic in
the BIN, burning this new BIN, and evaluating the change to your
car. If all goes well you will no longer get a check engine light
corresponding to a malfunctioning EGR valve. You have now successfully
worked with flags. Move on to constants.
The above combination indicates a 180º thermostat. The
owner most likely experiences around 180º engine temps while on
the highway but 220º engine temps when in traffic. This is because
the BIN doesn't activate one of the engine fans until a much higher
temperature. Change the BIN's fan on/off temps to work with your
180º thermostat (maybe a 190º ON value and a 183º OFF value). Burn
the new BIN and evaluate your changes. Does the fan come on sooner
now? If so, at what temperature does it come on? What temperature
does the fan go off? If all goes well the fan will come on at 190º F
and off at 183º F. At this time you may have other questions such
as: Why is only one fan coming on when I have two fans? or My temperature
guage in the dash doesn't display accurately? What are the answers? Research.
Research the answers. These are easy questions that most thirdgenners
know and have been covered many times in the 'other' messageboards.
If you have no other questions then modify other constants in the
BIN such as the Fuel Injector Flow constant in order to work with
the 24lb injectors. When you feel 100% comfortable with the flags
and constants then move on to the 2D tables.
A reasonable place to begin with 2D tables for the above
combination is with the Target Idle RPM vs. Coolant Temperature
table. The bigger cam may need a higher idle speed. However, unlike
the constants you will have to change multiple values. There is
an idle speed setting for many different coolant temperatures.
Make changes to the table, burn a new BIN, and then evaluate the
changes. Did the car idle at your new settings for the given coolant
temperatures?
3D Tables? I'll stop here. Describing how and what
to tune for a specific combination of modifications is a huge discussion.
We have only touched on a couple of changes above. There are numerous changes
that would have to be made for that combination. One could write
an entire volume of information on that very topic. The purpose of
this article is to give you a place to begin. You now have that place
to begin. You understand what it takes in terms of equipment and
software to program your own PROMs. You have the references that
you need for buying this equipment, modifying parts, and simple tuning
procedures. You also have the references to research advanced tuning
techniques.
Please note that everything
that you need regarding advanced tuning techniques as they relate
to BIN modification is not listed in an article for you to read
anywhere on the internet. What you need to know cannot be found
in some book that you can buy on Amazon.com. They exist in scattered
articles, messageboard subjects, mailing list discussions, and
old archives. There is no other way to learn
these more advanced techniques besides researching these messageboards,
mailing lists, archives, and scattered articles. It is now your
job to get from point A to point B. If you ever get stuck on
a topic and have seriously conducted the research to answer this
topic then post a message to the PROM board (or the GMECM list).
However, make your question extremely specific since broad questions
such as the one in the beginning of this section often go unanswered.
They go unanswered due to the fact that the answer would require
a book as thick as an encyclopedia. Nobody has the time to write
an encyclopedia. Furthermore, realize that those individuals
who are disseminating the knowledge have probably been asked
the same question 1,001 times and the answer is there on the
internet either in the messageboards, in mailing lists, or old
archives. Research and Experiment first. Ask questions later.
Scan Tools and Wide Band
Oxygen Sensors
You cannot successfully program a better chip for
your car unless you know what you want to change and why. That is
a given. A great way for determining what you want to change is through
the use of a Scan Tool. A Scan Tool is a tool that communicates with
your car's ECM through the ALDL port and displays your car's current
runtime statistics (such as O2 voltage, Coolant Temperature, Knock
Retard, Air Temperature, Spark Advance, etc). Although it is not
necessary to have a Scan Tool to successfully change your car's EPROM
calibration, they can be extremely helpful because they let you see
exactly what your ECM sees. Do you need more or less fuel? Do you
need more or less spark? Do you experience any knock retard and if
so, at what RPMs is the knock experienced? All of this information
can be determined easily by looking at certain parameters that are
displayed via the Scan Tool. In this writer's opinion - Beg, borrow,
or steal a Scan Tool. They are invaluable and worth their weight
in gold. However, it is important to note that some cars will benefit
from a Scan Tool more than other cars. This is due to the fact that
some ECMs transmit data at a faster rate across the diagnostic port.
TBI equipped vehicles will benefit less than TPI vehicles (except
for '85 TPI vehicles) due to the slower baud rate of their computers.
For example, a 0-60 run for a TPI equipped vehicle
may yield around 25 data points. However, a 0-60 run for a TBI equipped
vehicle will only yield 3 or 4 data points. ECMs with higher baud
rates will update data across the diagnostic link much quicker. See
the table at the end of this article to determine the baud rate for
your F-Body.
Some of the more popular Scan Tools that cost money
are presented below...
Diacom: http://www.rinda.com/auto/auto.htm
AutoTap: http://www.obdii.com
OTC: http://www.otctools.com
EASE: http://www.obd2.com/
AutoXRay: http://www.autoxray.com/index.htm
Datamaster: http://www.ttspowersystems.com/dm_dload.htm
Popular FREE ALDL software can be found via the following
links:
Craig Moates' Software: http://ice.prohosting.com/moates/gmecm/software.html
Jonas Bylund's 160 Baud WinALDL: http://w1.601.telia.com/~u60113744/software/winaldl/winaldl.htm
To use some of the programs above (most notably the
FREE programs) you will need a special cable that connects your laptop
computer to the car. Check out AKM Electronics or Steve Ruse. Both
of these companies make these cables. If you don't want to spend
money on one of the 'special' cables then you can build your own
through directions that are readily available on the Internet.
Link to AKM Electronics: http://www.mindspring.com/~amattei/akmelect.htm.
Link to Steve Ruse: http://www.geocities.com/steve3034/cables.html
Link to sites that have directions on how to build
a cable:
http://www.mindspring.com/~amattei/assembly.htm
http://www.techedge.com.au/vehicle/aldl8192/8192hw.htm
http://www.andywhittaker.com/ecu/aldl_hardware.htm
http://pweb.de.uu.net/pr-meyer.h/aldl.htm
http://ice.prohosting.com/moates/gmecm/software.html
Another extremely useful piece of equipment is a Wide
Band oxygen sensor. Oxygen sensors measure the amount of oxygen in
your exhaust and report an air-fuel ratio (AFR) as interpreted through
a voltage measured at the Oxygen sensor in Millivolts. The stock
oxygen sensor in all EFI F-Bodies is a one-wire sensor that is only
accurate around a certain AFR - 14.7:1. Thus, when shooting for max
power (lower AFRs) the stock oxygen sensor is not reliable and should
not be used. This is where Wide Band oxygen sensors step up to the
plate. They are very accurate across a wide range of AFRs. However,
Wide Band oxygen sensors tend to be very expensive (in the neighborhood
of $1000!). But, there is an alternative. That alternative is the
DIY-WB project (Do-It-Yourself Wide Band). You can build your own
Wide Band oxygen sensor for around $200! All the information that
you need is located at http://www.diy-wb.com/.
Please take note that this project is a non-profit project developed
by members of the Do-It-Yourself EFI community through the EFI mailing
lists at http://www.diy-efi.org.
Be wary of other products that have used this information to develop
a profit. Stick with the DIY-WB and support the DIY community!
Newbie Questions
The most frequent 'newbie' questions regarding PROM
Burning are:
- Question: Which Scan Tool should I use? What
are the Pros/Cons of each?
Answer: This is an extremely
difficult question to answer since there are
so many tools available to the public. The
more popular ones are listed above (Diacom,
Ease, AutoXRay, OTC, and the Free Software).
However, all of these programs can be arranged
into 2 categories: laptop scanning software
or handheld scanning unit. The first question
that you must ask yourself is if you have access
to a laptop. If you don't have access to a
laptop then you can only consider one of the
handheld units (AutoXRay, OTC, etc). If you
do have access to a laptop then ask yourself
how much money you have available to purchase
a Scanning Program. Depending on your budget
you will either need to go with the Free Software
or a program such as Ease, Diacom, etc. A general
rule of thumb is that the handheld units give
you less flexibility and less functionality.
So, keep that in mind when buying a handheld
scanning unit such as AutoXRay or OTC. For
example, using the 'Record' feature of the
AutoXRay will only give you one datapoint every
second. Contrary to this, laptop scanning software
will yield many datapoints each second
while in record mode. This may not sound like
a big deal. However, when doing a 0-60 run
with a total of 6 seconds from 0-60 the AutoXRay
will only yield 6 datapoints whereas Diacom
or Ease will yield possibly 100. This is a
huge difference. Another example of this decreased
flexibility and functionality is that many
of the laptop scanning programs have options
that allow you to graph the data, export the
data, print the data, etc. Graphing is invaluable
in terms of plotting one engine condition vs.
other engine conditions. Furthermore, since
the laptop scanning software shows you the
ECM parameters on the laptop's screen, you
have the ability to view many parameters
at one time. The handheld units will usually
only display one parameter at a time. In defense
of the handheld units they are much cheaper
and require nothing else to communicate with
your ECM. I began my scanning experiences with
the AutoXRay handheld scanning unit. Later,
when I acquired a laptop, I purchased Diacom.
The difference in terms of flexibility and
functionality is night and day. It is important
to note, however, that if you are going to
use laptop scanning software then the old addage
'you get what you pay for' rings true. Programs
such as Diacom, Ease, and Datamaster cost money.
These companies get paid for adding useful
features and functionality to their programs.
In the past this has meant that these programs
offer more flexibility, more functionality,
and more user support than their free software
counterparts. However, this is slowly becoming
not true. Both Craig Moates' and Jonas Bylund's
free ALDL software are very popular among the
DIY crowd and both are very functional programs
(and get even more functional as time progresses).
All free software programs require you to make
or buy a cable that can be used to connect
your laptop to the ECM's communication port
(ALDL connector). On the other hand, some of
the programs that cost money (like Diacom)
come with a cable (or multiple cables to connect
to various automobiles). The differences between
Diacom, Ease, and Datamaster are often the
subject of conversation. However, if you are
set on buying laptop scanning software then
you can't go wrong with any of these. The only
real questions to ask yourself regarding these
programs are: What operating system exists
on my laptop and how fast is my laptop. If
you are running DOS on your laptop or the laptop
is slow (less than a Pentium 133) then choose
Diacom. Diacom runs in DOS and can run on very
slow machines (I've even heard of it running
on a 286!). However, if you are running Windows
and your laptop is speedy then go with Ease
or Datamaster. The 'Windows' environment is
hard to beat. In the end, your decision will
be based on the availability/type of the laptop
and your budget. Just keep in mind the information
presented above when making your decision.
-
-
Question: Which Editor should
I use? What are the Pros/Cons of each?
Answer: Highly dependent upon
several factors; namely the amount of money
you have to spend, the type of computer you
are using (including Operating System), the
features you want, and what you feel comfortable
using. I have limited this discussion to 3
Editors: WinBin, GMEPro, and TunerCat. However,
be advised that there are other Editors out
there. I am discussing these 3 because they
are the most popular. If saving money is your
most important consideration then choose WinBin.
It is 100% Free of charge. If you are willing
to spend money in order to receive more 'bells
and whistles' and more support then choose
either GMEPro or TunerCat. Both of these programs
are excellent. If being able to run your Editor
in a DOS environment is your primary concern
then choose GMEPro. Both WinBin and TunerCat
require a Windows based operating system. I
quick list of pros and cons are listed below:
Program |
Pros |
Cons |
WinBin
|
Program is 100% Free
Definition files are 100% Free
Can create custom definition files |
Definition files are few and far between
Definition files are harder to create
Patches/Fixes by the author take much longer
No Graphing or Compare feature |
GMEPro
|
Good Support
Solid Program
Runs on slow DOS laptops with few problems
Can create custom definition files |
No Graphing or Compare feature
Each Definition file costs more money
DOS based environment is antiquated for some
$80 for Editor (1 Definition file included)
$50 for each Definition file
$100 for info to create custom Definition files |
TunerCat
|
Great Support
Solid Program
Compare feature
2D and 3D Graphing feature
Many more Definition files available
Can create custom definition files |
Runs best on faster machines (Pentium
133)
Each Definition file costs more money
$70 for Editor
$20 for each Definition file
$40 for Definition file Editor |
-
Question: Why can't I read my
BIN with the demo version of TunerCat?
Answer: The evaluation version
of TunerCat available on
TunerCat's
site is delivered with the $42 definition
file. This definition file is for a TBI Truck
ECM (1228747) and, therefore, does not work
with ANY F-Body BIN. To work with a '85-'92
F-Body BIN you will need a TunerCat Definition
file that matches the BIN you are attempting
to use ($1F, $32, $32B, $6E, $8D for TPIs or
$4D, $61 for TBIs as specified in the table
at the end of this article). This makes the
evaluation of TunerCat difficult because the
definition file that you will need for your
F-Body BIN is not readily available unless
you buy it from TunerCat. However, you can
always send TunerCat an e-mail and request
a Demo copy of the definition file that you
need. In many cases he has supplied the necessary
definition file for evaluation purposes. FYI,
at the time of this writing the price for the
definition file is $20. Please visit
TunerCat's
site for more information on purchasing
the definition file. An alternative to buying
the definition file for evaluation purposes
is to evaluate TunerCat for the TBI Truck ECM
(1228747). You can obtain a 747 BIN file from
the 'diy-efi' site. There are many 747 BINS
located at
ftp://ftp.diy-efi.org/pub/gmecm/bin_lib/1227747%2042/
-
Question: Where can I get the
definition files?
Answer:
- TunerCat - TunerCat Definition
files are called TDFs and are delivered
with a '.tdf' file extension. They are
only available through TunerCat at a price
of $20 each. Please visit TunerCat's
site for more information on purchasing
the definition file.
- WinBin - WinBin Definition files
are called ECUs and are delivered with
a '.ecu' file extension. In most cases
the actual filenames contain the mask (either
8D, 6E, 32, or 32B) along with some type
of version number. These files are available
in several locations. Keep in mind that
since ECU files are free and easily modified,
they tend to be available at many locations.
The most popular locations for these files
are:
DIY-EFI Site at: ftp://ftp.diy-efi.org/incoming/.
ZaphodB's site at: http://www.area51.org.il/~zaphodb/gmecm/.
Craig Moates' site at: http://ice.prohosting.com/moates/gmecm/software.html.
- GMEPro - GMEPro Definition files
are called EPEs and are delivered with
a '.epe' file extension. These files can
be obtained through contacting Terry at terryk@foothill.net.
-
Question: Where can I get a
BIN?
Answer: I would first suggest
that you read the BIN from the chip in your
car. If you aren't willing to do this then
there are several places on the internet that
have BINs for public download. Two of the more
popular ones are listed below...
- GMECM BIN Library: ftp://ftp.diy-efi.org/pub/gmecm/bin_lib/.
- Michael Davis' Page: http://www.eecis.udel.edu/~davis/z28/.
-
Question: My BIN won't load
into the program or the PROM data appears wrong. What is the
problem?
Answer: The biggest reason
that this occurs is because someone is attempting
to utilize the wrong defintion file.
Ensure that you have the correct definition
file selected/loaded into the program. If you
are sure that you have the correct definition
file selected then try another BIN that is
of the correct Mask. It is possible that you
are attempting to work with a corrupted BIN
file.
-
Question: What BIN should I
start with? Should I start with the BIN that I downloaded from
my chip or is there a better place to start?
Answer: In most cases you
should start with the BIN you downloaded from
your chip. However, the general rule of thumb
is that you want to use the latest BIN that
GM released for your make/model vehicle. Two
of the most notable BINs for F-Bodies are presented
below:
- 1986-1989 TPI F-Body with a 350ci Engine
and automatic transmission - The best BIN
to start with is the ARAP BIN. The ARAP
BIN is a $6E binary developed by GM and
used in the '89 TPIs that were delivered
to the press. This BIN is a plug and play
situation for the 1989 350ci Automatic
F-Bodies since they are already running
$6E code. For the '86-'88 F-Bodies you
will need to either unplug your cold start
injector or just use a cold start injector
plug kit since the $6E binary gets rid
of this piece of equipment (cold start
injector plug kits are available through
either Accel or Arizona Speed and Marine).
For all MAF cars you will also need to
make sure that the fans are set to "Normal
Operation" since the stock ARAP has this
operation reversed. This BIN can be found
at both Craig
Moates' page and ZaphodB's
page as well as the GMECM
BIN Library.
- 1990-1992 TPI F-Body with a 350ci Engine
and Automatic Transmission - The best BIN
to start with is the AUJP BIN. This BIN
is available at ZaphodB's
page as well as the GMECM
BIN Library.
-
Question: Where do I start?
What do I modify in the BIN? How do I know what to change?
Answer: Read the sections
entitled Important
information for beginners and Modifying
the BIN located previously in this article.
How EPROMs work
At this point I would suggest learning the specifics
behind what a PROM is and how they work. Xtronics has done a wonderful
job at covering this in detail. For a full description on what PROMs
are and how they work follow this link...
http://www.xtronics.com/memory/how_EPROM-works.htm
EPROM Reference for TPI
and TBI Thirdgen F-bodies
ECM, EPROM, and Calibration reference |
Year (TPI eng.) |
1985 |
1986 |
1987 |
1988 |
1989 |
1990-1992 |
ECM Type |
C3 |
P4 |
P4 |
P4 |
P4 |
P4 |
ECM ID |
1226870 |
1227165 |
1227165 |
1227165 |
1227165 |
1227730 |
EPROM Type |
2732 |
27C128 |
27C128 |
27C128 |
27C128 |
27C256 |
BIN Size |
4Kb |
16Kb |
16Kb |
16Kb |
16Kb |
32Kb |
Mask (Calibration) |
$1F |
$32 |
$32B |
$32B |
$6E |
$8D |
Engine Management |
MAF |
MAF |
MAF |
MAF |
MAF |
Speed Density |
Baud Rate |
160 |
8192 |
8192 |
8192 |
8192 |
8192 |
MemCal |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Bare EPROM |
Yes |
No |
No |
No |
No |
No |
Year (TBI eng.) |
1988 |
1989-1992 |
ECM Type |
C3 |
C3 |
ECM ID |
1228063 |
1228746 |
EPROM Type |
2732A |
2732A |
BIN Size |
4Kb |
4Kb |
Program ID (Calibration) |
$4D |
$61 |
Baud Rate |
160 |
160 |
MemCal |
No |
No |
Bare EPROM |
Yes |
Yes |