GM ECM injector driver capacity

[Bruce Plecan]

-----Original Message-----
From: Ken Kelly <kenkelly at lucent.com>
Subject: Re: GM ECM injector driver capacity


>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.

OK, then sent me what you'd consider to be the right inductive
load, and I'll test that.

Upon reflection,  the 165 was used to fire a single TBI so it,
can do a "I think 2 ohm load".  Also, PPF wrote in the last
couple mounths about grounding a terminal to current limit
the 730, and In the 165 TBI application they tied two wires
differently for the TBI.
Cheers
Bruce

>
> 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
>
 -----Original Message-----
>> >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 6 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.