GM ECM injector driver capacity

[Ken Kelly]

Bruce & Brock,
	Be careful with testing using resistors to simulate the
Injectors. I assume you mean you are going to use a bunch of
12 ohm resistors to simulate the Injectors. The injector is
really an Inductor. You may be able to run the ECM all day
with the resistors, and still blow it up the first time you
stick the inductive load on it.

	It makes sense to use the Resistors in your Bench racing
senario where you are looking at the ECM output waveform. It
is just the conclusion that if it works with resistors it
will work with injectors that is eroneous. 

		Ken

Bruce Plecan wrote:
> 
> -----Original Message-----
> From: Jennifer and Brock Fraser <fraser at forbin.com>
> To: diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
> Date: Monday, August 24, 1998 12:30 AM
> Subject: GM ECM injector driver capacity
> 
> >Does anyone know what the injector driver capacity is on GM ECM's?
> 
> On the Howell four barrel Holley conversion he wires the the injectors
> to two groups of two.  Meaning 2 in series, and then in parrarellelllel
> witha second group, BTW they are Peak+Holds.
> 
>  To be
> >specific, I'm curious about the 165 ECM.  I see that on a multi-port V8
> >application, all 8 injectors are batch-fired by 2 outputs.  Is it possible
> >to attach 8 more injectors to these two outputs (series, parallel??) to
> fire
> >16 injectors simultaneously?
> 
> So far, in my limited testing the outputs of both the 165 and 730
> while they use two terminals, they tie to one driver.  Also, several
> other folks have said this.  On the one chip I have had run on the
> 730 it does fire all 8 at the same time, once per crank revolution.
> 
>   Info pertaining to the 730 ECM would be good
> >as well...  The injectors would be high impedance (12-14 ohm) ones just
> like
> >the stockers.
> >
> >If this isn't feasible, what would it take to make the GM driver(s) also
> >trigger another external driver for the extra injectors?  Again, the desire
> >is to fire the second batch of 8 at the same frequency and P.W. as the
> stock
> >batch of 8.
> 
> As testament to the the gm ecms I've run two IACs off the stock
> ecm that only had one, with not problems.
> 
> If you can set up a resistor network for what you want to fire, send it
> to me, and I'll bench run it,  but you'd have to stand good for replacing
> the ecm if it dies,  usually they cost me $50-60.
> 
> You might consider using two ecms.
> >
> >
> >Thanks,
> >Brock
> >
> Cheers
> Bruce