Fw: [Diy_efi] More Analog diagnosis

[Geoff Harrison]

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.

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
_______________________________________________
Joe, It may be the unit is waiting for ign pulses to fire the injectors.
What you may be seeing is the cold start mode. That's one scheme I have in 
mind for a 555 timer based EFI.
Try hooking it up to an ign system, still with the noid lights.
If you can send me scans or photos of both sides of the PCBs I may be able 
to shed some light on it. (geoff_h at smartchat.net.au)
BTW, the 555 timer idea is not dead. It sometimes seems as though I 
re-inventing the wheel. I made the mistake of trying to do too much with 
it - ignition control. One thing at a time.

Geoff