[Diy_efi] More Analog diagnosis, spark sync

[Mike]

Do you have a starter or primary spark feed, the newer digital EFI
units need at least a sync feed, mine also has a signal
from the starter,

In other words how would the EFI unit know the engine has
started and wouldnt it sync the injector firing on the spark
so there is some repeatability of injector firing versus spark
in other words *speed*  etc.

ie. Can you imagine how the engine would run if the EFI injector
firing didnt have any way to sync with the engine speed, my thought
is it wouldnt be very repeatable, hence it prob wouldnt run if
it didnt have a feed hence seeing what you are now that it just stops
after a few seconds because its wired to assume there is a spark fault.

Also I dont know what a 'noid' light is, I'd suggest using a LED instead
just in case there is an issue with injector drive current, or at least
a bulb that is no less resistance than a high impedance injector.

Sounds like a fairly simple unit, if there are less than a 100 components,
it wouldnt take more than 2 hrs to derive a schematic at least
in black box form if there eg ICs with no numbers ... imho...

Regards from


Mike
Perth, Western Australia
VL Commodore Fuse Rail that wont warp or melt !
Twin tyres for most sedans, trikes and motorcycle sidecars
http://niche.iinet.net.au





At 08:43 AM 10/13/05, you wrote:
>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.
>
>My thought is something in the power supply is bad as
>the effect is the same for all the injectors.
>
>I don't have a schematic.  There are one set of
>components for each injector except there is one power
>transistor and capacitor all by themselves.
>
>Thanks,
>
>Joe 
>_______________________________________________