Mods to '85 GM TPI ECM

[Craig Marcho]

Hi Jim! We have something in common... I've got an '85 Corvette which uses
the same ECM as you. First, like others mentioned, you need to find the ECM
and broadcast code from your EPROM. The code on mine is HLH3200, which
seemed pretty common on '85 Corvette's. If your ECM has a big 1226870 on it,
then you've got the slower ECM like me. The other ECM that has been talked
about is the 1227165 that was used on '86-89 F and Y cars (and a bunch of
others I'm sure) and is much faster at spitting out ALDL data than our '870
ECM. If you do have the '870 ECM, then the chip that you'll need to program
is a 2732A, cost a few bucks each. I use the Needham's PB-10 burner, which
goes in an ISA slot and cost about $125. You'll also need an EPROM eraser, I
use the DataraseII, about $50. You can download Tunercat from
www.tunercat.com, that'll help get you started with changing things. Anyway,
get back with the broadcast code, and you'll be able to get alot more help.
I'm really new at this, but I've been working alot with the '870 ECM, so I
may be able to help you once we know what you've got.

Craig M.

> Hi, my name is Jim Brady and I just joined the list a few moments ago.  My
> current project is my '87 Monte SS.  My Monte is equipped with the GM
> TPI(Tuned Port Injection) system consists of an '85 computer(I
> assume I have
> an '85 computer because it had a Bosch MAF burn-off box attached
> to it) with
> '87 hardware.  My original motor was a 305 and the system worked perfect.
> My new setup is a 383(stroked 350) with a T56 manual trans.  The only
> changes I have made to the system since I upgraded from the 305 to the 383
> is 24lb/hr injectors and a fuel pressure regulator.  Everything
> works great
> except full throttle.  I understand full throttle switches the ECM to open
> loop mode leaving the EPROM to feed the system pre-determined
> values.  Aside
> from improving my full throttle condition I would like to monitor the
> parameters of the running motor.  What do I need to approach this project?
> I assume an EPROM burner, cable for the aldl connector and software.  What
> can I manipulate with the software?  How about the EPROM.  I am
> new to this
> and would appreciate any help you can give on this matter.  Thanks.
>
> Jim Brady
> '87 Monte SS 383 TPI 6 speed
>
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