P&H Injector Interface

[Garfield Willis]

On Sat, 20 May 2000 10:44:12 -0700, romans at starstream.net (Romans, Mark)
wrote:

>On the 165 and 730 ecm, batch fire, splicing at the ecm would be by far the
>simplest solution.  Especially if it were done right, ie: plug and play with
>correct connectors.  Since the environment is already as computer friendly
>as a car is going to get, power, ground, injector leads are all right there.
>I would also splice if necc to run P&H injectors.  Wouldn't be hard
>especially with the batch fire set up.  Sequential would obviously be more
>complex, but I would think much simpler at the ecm than at the injectors.
>Mark

Ahhh, this just reminded me of another thing I wanted to broach. (thanks
for the input above, BTW Mark).

I think we've got a way to do all the above with nary a splice, but
here's part of me ongoing puzzle. On some of the batch fire ECMs,
typically (if I got my lessons down now :) there are a batch of sat
injectors driven off one or two wires coming from the ECM. Even in the
case of the 749 which can fire P&H, only two of such are driven from a
single wire. This all makes sense from a current carrying capacity
standpoint of both the wires and perhaps most especially the pins.

NOW, let's do some supposes: spose that someone wants/needs to go to
P&Hs to get where they're going, and has a harness & ECM that have
previously driven some number of sat injectors. At the ECM, we still
have only a couple wires, each that go out to say a bank of worst-case 4
injectors (?).

Now, if we put the P&H interface driver near the ECM, without some
rewiring, we're gonna be having to drive possibly 4 P&H injectors from
this wee wire and pin? Ummm, I'm not sure about that one. See the issue?

Taking the sequential ECMs to P&H would of course be much less
problematic ala the above issue, since they each have a wire/pin
dedicated to each injector. Driving one P&H where a sat inj used to be
isn't a worry, it's when you forsee driving banks of P&Hs from the same
wiring and connector pins that drove banks of sat injs.

Soooooo, my next question would be: where in the harness does the "bank"
wire from the ECM get split out into individual wires for each injector?
I'll bet it's on the other side of the firewall. Argh.

Gar

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