[Diy_efi] Key-On Power for 7730

Lee M. Lemoine llemoine
Thu Sep 28 04:30:26 UTC 2006


Forgive me .  I meant rectifier diodes.

On 9/28/06, Lee M. Lemoine <llemoine at gmail.com> wrote:
>
> I think i understand what your saying here, not being familiar with coils
> or any of that sort of thing (Hey, i was born in '82 and fuel injection is
> older than i am)...  That being said, i've never once tuned a carbeurator.
>
> I believe your problem is that you don't have the correct setup on your
> ignition.  You need a feed thats hot during cranking and in the 'on'
> position.  I take it the ACC circuit shuts down while cranking also ?
> (radio, wipers, etc)  That'd be my first guess.  If you can't get constant
> power during cranking, a few things could be tried...
>
> My thought on this instance, would be to utilizing a set of  zennier
> diodes to power the ECM's "key on power leg"using the "IGN2" while
> cranking.  Simply using diodes, your essentially jumpering from the 'IGN2"
> position back to your "IGN1" circuit, but preventing the IGN2 circuit from
> powering anything up in the car other than the ECM.  I'd also toss in a
> large-ish capacitor in line to 'fill in' that "gap" you speak of when the
> ignition switch jumps the gaps as the key turns through different
> postiions.  This way a new branch off of your IGN1 circuit is hot in both
> the start and run positions.
>
> If you need a schematic or further explanation, let me know i can draw out
> a schematic.  It shouldn't cost too much as the ECM doesn't pull too much
> current during cranking -- the diodes will be the largest cost, with the
> capacitor being secondary.   It's a simple wiring job and can be done at any
> convenient point in the wiring harness (so you don't have to picture taking
> your column switch apart to accomplish this!)
>
>
>
> On 9/27/06, Clair Davis <clair.davis at charter.net> wrote:
> >
> > Background... I've got a 69 Plymouth Valiant I'm multipoint-injecting
> > with a
> > 7730 box.  I've got two wires left to run, and one of them is killin'
> > me:
> > Key On Power.
> >
> > On my old Plymouth, the ignition switch has 5 wires: BATT, START, ACC,
> > IGN-1, and IGN-2.  IGN-1 is the "run" power to the coil, dropped down
> > with a
> > ballast resistor to keep the coil happy.  IGN-2 is 12V straight to the
> > coil
> > for hotter sparks while cranking.
> >
> > The IGN-1 circuit is DEFINITELY dead while cranking, and IGN-2 is ONLY
> > hot
> > while cranking.  Once the engine fires, you let up on the key, the
> > switch
> > rolls back to IGN-1 and you go on about your way.  Problem is, I can't
> > tell
> > how long the dead skip is in the transition between the two circuits.
> >
> > Is this a problem?  Seems like it might be, as the "key on" signal seems
> > to
> > be the trigger for the whole start-up routine with the ECM.  Is a GM
> > ignition switch one where there is no break in the power from "run" to
> > "start" and back, or am I overthinking things?  Mopar guys that run MSD
> > ignitions splice IGN-1 and IGN-2 together for the MSD to work, but
> > that's
> > hardly the same animal.
> >
> > Thanks in advance!
> >
> > Clair
> >
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> >
>
>
>
> --
> Sincerely,
> Lee M. Lemoine
> KB1NQI  - Amateur Radio
> http://www.turbochargedsoul.com/
> '06 Subaru Legacy GT Limited - 250/250 AWD 5EAT
> '93 Chevy Cavalier Z24 Convertible - 300/330 FWD 5MT (Mclaren Turbo!)




-- 
Sincerely,
Lee M. Lemoine
KB1NQI  - Amateur Radio
http://www.turbochargedsoul.com/
'06 Subaru Legacy GT Limited - 250/250 AWD 5EAT
'93 Chevy Cavalier Z24 Convertible - 300/330 FWD 5MT (Mclaren Turbo!)




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