Re: EPROM Programming

[Shannen Durphey <shannen@grolen.com>]

WEG1192@aol.com wrote:
> 
> Hello All,
> 
> I am interested in modifying my GMECM EPROM. I have read Programming 101 and
> the tuning tips. So is it as simple as getting an EPROM burner, getting
> tuning software like Tunercat, getting their chip TDF file for the ECM that I
> have, making the changes, and then burning the chip? 
Yes, in the same way that building a good engine is as simple as
buying tools and parts, then putting them all together.  The mechanics
of actually "modifying the chip" are extremely simple.  The magic is
in making a good chip, which will take time.

>Will the .bin files on
> the DIY-EFI site work without any changes? 
Yes, they will work exactly as designed in the same application they
were designed for.  Anything else is just a guess.

Or do I have to remove the VATS
> and EGR functions? 
You need to disable or bypass VATS when the application calls for it. 
The same is not always true for EGR

In reading the tuning tips by Dr. Bruce Plecan, it appears
> that you make a change, drive the car, then make another change. Isn't that
> very time consuming since you have to reburn the chip every time, or is he
> using some real time program he didn't mention?

Yes, it is very time consuming.  That is why the people that have
burned so many chips have such a thorough understanding of what it
takes to make a "good" chip.  That is also why some people here lose
patience with list members that don't want to spend even a little time
looking for info.  

> 
> Last, does anyone know if the fuel pressure on a TBI system changes with
> engine vacuum like it does on a TPI system?
For GM systems, generally no.

You're asking about 14 years worth of systems.  To put your question
into perspective, asking about disabling VATS is like someone asking
if they have to remove the front driveshft in their Jeep, with no
other info about the Jeep, or the use it will see, or the reason they
want to remove the driveshaft.

Have you got a swap in mind?  Are considering TBI or TPI?  Are you
looking at any particular donor vehicles?  This type of info might net
more better answers for ya. : )
Shannen
> 
> Thanks for the help.
> 
> John Wilson
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