[Diy_efi] More Analog diagnosis - Summary

[Joe B]

Allow me to collectively answer all the answers.

My limited electrical knowledge (I'm a mech engineer)
lead me to the thought of a mis-match of the
resistance values.  The resistance of
what-I-thought-was-an-LED-light was around 20 ohms
while the frozen shut injectors measure at 2.6.  All
four of the injectors, exactly.  I thought a lower
resistance would lead to a higher current draw, so the
lights wouldn't goof things up that bad.  I also
detected the dropping voltage with a high impedance,
digital volt meter without any load on the injector
leads.

I attached the system to a piece of partical board so
I could easily plop the board next to my Camaro and
hook it up.  I am using the needed signals from the
car to test the unit.  So all required signals into
the unit to function are there.

I am missing the temp sensor so I hooked up a resistor
to the unit.  I can't remember what the value is but
according to the web site of the parts supplier, it is
probably low temp, so the unit is in cold start mode.

I'll try a resistance more in the 200 degree temp
range and see if I can rig up LED's in the proper
resistance range instead of injectors.

Any other thoughts would be appreciated.



--- Rick McLeod <dunvegan at sbcglobal.net> wrote:

> Instead of incandecent lamps for the noids, use
> LED's,
> much lower resistance, and should work on either low
> or high impedance driver systems. Make sure there is
> a
> limiting resistor of correct value, to obtain the
> correct on current, other than that should be good
> to
> go.
> 
> BTW, I agree w/ the cold start theory, try placing a
> variable resistor in the sensor for temp, and set to
> simulate a warm engine start, see if the flickering
> decreases or ceases.
> 
> Good luck.
> 
> --- Geoff Harrison <geoff_h at smartchat.net.au> wrote:
> 
> > Good point. I assumed being an older unit would be
> > designed for low 
> > impedance, therefore assumed would drive a noid
> > light, which would have a 
> > very low cold resistance, where as the injector
> has
> > inductance.
> > 
> > Several manuals I have seen describe the use of
> noid
> > lights for testing 
> > injector wiring and ECM pulses while cranking. Are
> > they all wrong?
> > I suppose it depends on the wattage of the noid
> > light.
> > 
> > Geoff
> > ----- Original Message ----- 
> > From: "Lee M. Lemoine" <llemoine at gmail.com>
> > To: <diy_efi at diy-efi.org>
> > Sent: Thursday, October 13, 2005 11:37 AM
> > Subject: Re: Fw: [Diy_efi] More Analog diagnosis
> > 
> > 
> > was thinking similar, high impeadance on low
> > impeadance.
> > 
> > On 10/12/05, Djfreggens at aol.com
> <Djfreggens at aol.com>
> > wrote:
> > >
> > >  In a message dated 10/12/2005 9:33:23 P.M.
> > Eastern Standard Time,
> > > geoff_h at smartchat.net.au writes:
> > >
> > > Joe Boucher wrote on Oct 13 2005
> > >
> > >
> > > There is a small chance someone may remember I
> > have an
> > > older analog EFI unit I bought at a swap meet.
> > After
> > > some fangling with it, it is functioning except
> > for
> > > one thing.
> > > I put some noid lights in place of the
> injectors.
> > I
> > > would switch power to the unit and the lights
> > would
> > > start flickering as they should, then over about
> 2
> > > seconds, the light intensity would die untill
> the
> > > lights went out. This happened every time I
> cycled
> > > the power.
> > >
> 
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