EEC-IV Modifying for low impedance injectors

[Paul S. Draper]

Frederic Breitwieser wrote:

> Yes Paul, most OEM ECMs designed for high impedance injectors will fry their
> output stages if lower impedance injectors are used... sorta the same
> concept as putting a 2ohm speaker on a 8 ohm stereo - have your fire
> extinguisher ready :)

That's what I don't want to happen.  :-)  But I do have a Fire Extinguisher in
my car just in case!

> However all is not lost... I've opened two EEC's and it appears the injector
> drivers are nothing more than transistors...

That's what I've read.

> therefore these could be
> changed to higher current capable devices,

I was thinking of making a Junk Yard trip and picking up one of each EEC, one
that I want to use, and one that was designed to run Low Impedance injectors.
Then either getting new transistors to match the low z eec, and installing them
in the other EEC, or just swaping them.

> Its nothing more than an inductor in parallel with the ECM output and
> ground, which then feeds a 1k resistor driving a large MOSFET which connects
> to 12V Battery, the low-impedance injector, which in turn connects to
> ground.
>
> Hope that helped

Yup, it did.  Though I really should stop looking at this EEC Schematic I
found...cause it has Battery Voltage,12v, going through a 390 ohm resistor in
series  and a .01uF cap in parallel, then into a 5 pin IC, out of the IC to a
3.6v? 5W diode in parallel, and a 1000pF cap in parallel, then to the injector
then to ground.  The 5 pin IC is what is confusing, or is this the MOSFET?  I'm
not an EE...just a ME with just enough electronics knowledge to get myself in
trouble...  :-)

Thanks!

Paul
--
Paul S. Draper
psd105 at psu.edu
1969 Mustang 302 Twin Turbo Project
http://www.geocities.com/motorcity/factory/9893