Re: V8 '165 harness modifications

[Gabe <gellett@earthlink.net>]

Ernst denBroeder wrote:

> List:
>
> Need some help here...
>
> I'm in the process of patching a MAF harness from an 87-88 F-body car so
> that I can use it in a retro-fit application.  (3 wire power connection
> when done, none of this power and ground all over the place nonsense!)
>
> 1) The cold start (9th) injector circuit puzzles me... and I don't have
> the hardware infront of me to look at (just the harness, the intake and
> all is still packed away from my recent move).
>
>     |----------\
> Inj |          |
>     |-----\    |
>           |    |
>           |    |
>      |----/    |
> Temp |         |
>      |---------*---------> 12V

Do as Mike suggested, use the '89 code, or...

Feed the coolant temp sens with +12 when cranking.  If the temp < 100deg F then
the ckt is closed and the injector will inject during crank.


>
>
> Why does 12V go to the temperature sensor as well?  I thought the function
> of this sensor was to ground the (-) of the 9th injector to energize it?
> Or do I have this all backwards, as I understand it the 9th injector is
> powered anytime the coolant temp is below X degrees... am I right?
>
> 2) There is a seperate O2 ground wire (tan) leading off of the harness,
> where does this normally connect to on the vechicle?  Can I wire this to
> my common harness ground point or would it be better tied to a point
> closer to the actual sensor?
>
> 3) 4th gear input to the ECM... this harness was previously wired to a
> TH700R4.  My application uses a TH200R4, which does not have the 4th gear
> output.  What should I do with this (now) unused input?  Ground it or
> float it?  What does the computer use this input for?  Highway spark?
>
> 4) Air injection: the project car does not have air injection...
> does the computer sense if the Air Select and Air Diverter solinoids are
> disconnected?  If so, what resistance does the ECM need to see to fool it?

As far as I know (I am running '89 code w/o air inj with no trouble) it does not
monitor air injection.....

Can't help on the other 2 off the top of my head, if no one else answers, I will
look it up....

Gabe

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