GM 7 and 8 Pin HEI modules (2nd try)

[Joe Boucher]

I tried to send this message yesterday.  It didn't get to the list either
because my servuce provider screwed up (it was hosed most of the weekend)
or I broke a rule.

If anyone one wants the gif file, email me.


>Date: Mon, 27 Oct 1997 21:48:32 -0600
>To: DYI-EFI
>From: Joe Boucher <jboucher at startext.net>
>Subject: GM 7 and 8 Pin HEI modules
>X-Attachments: C:\Eudora\Attach\schematc.gif;
>
>I promised earlier to look up  a Hot Rod article about using the 7 pin HEI
EFI module in a 4 pin HEI distributor.  I haven't found the article but I
found something almost as good.  It is wiring diagrams for the 7 pin
internal coil HEI (Figure 3) and the 8 pin external coil distributor
(Figure 4).  (Notice the "Diagram provided courtesy of GM.")  These are
from "Mitchell's Electronic Troubleshooting Guide" from HP Books. (ISBN
0-8470-0023-0)
>
>The four numbered wires in Figure 4 are id'ed in the '88 truck repair
manual as:
>430 - reference
>453 - ECM Internal Ground
>423 - EST
>424 - By-Pass.
>
>I think the 8th pin is just a ground wire not id'ed as a pin in the 7 pin
module.
>
>If the two modules are compatible, then any GM EFI wiring harness with a
distributor can be used on any motor that had a GM HEI.  Including the
great HERESY, FORD!!!!!!!  There is a company selling a Ford distributor
with a GM HEI head.  So, maybe you could use the 7 pin module and adapt a
GM EFI to it. ("Dogs and cats living together!!")
>
>I will continue to look for the article.
>
>
Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban