555 EFI

[Don.F.Broadus at ucm.com]

When I was at a Research Lab we used a circuit to run the Dyno engines so I
know it works. I cant scan it but could fax it to
someone who could. The circuit triggers from dist pulses from the HEI module
REF lead to a cd4013 Flip/Flop and cd4538 Dual monostable. The Q output of
the 4013 goes to pin 2 of a 2 input And gate cd 4081. The Not Q goes to pin
5 of the 4081. Pins 1 and 6 of the 4081 are tied together and go to the Q
output of the 4538. The pulse width is controlled by a 100K pot and .1 mfd
cap on pin 2 of the 4538. Pins 4 and 3 of the 4081 go to power transistors
that fire the injectors. 10K resistors are in series with the base of the
transistors.  A Throttle position sensor can be used  in place of the 100K
pot and will vary the pulse width from  approx .5 to 10 Msec. If the TPS is
10K add resistors on each end of the pot to get 100K total. Place a switch
on the Bypass line of the HEI, open to start, Ground to run.  Now to the
part I haven't tested yet. A FORD MAP sensor outpus a frequency in relation
to the Vac present. Connect the output of the FORD MAP  to the HEI module
EST input. After the engine starts flip the switch to RUN and the FORD MAP
will output about 160 Hz to the HEI mod. This should advance the timing. As
you Rev the engine the Freq. will go down and  retard the timing. If you
want to add a coolant sensor and rather use a Voltage output MAP. Use a
Summing amp config on the input of the monostable and a VCO to control the
timing. Just my .02$ for a circuit that will run a engine for testing at a
junk yard or on a stand.

                                                            Don




> -----Original Message-----
> From:	AL8001 at aol.com [SMTP:AL8001 at aol.com]
> Sent:	Friday, January 15, 1999 8:45 AM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: 555 EFI
> 
> In a message dated 99-01-15 09:33:21 EST, nacelp at bright.net writes:
> 
> > I'm looking to keep this as much as an entry level thing, meaning
> >nothing but 555s, op-amps, and a final drive.  
> 
> Something like this would be great for testing junk yard engines or
> moveing a
> car that's a "work in progress" when the ECM and related parts are gone.
> 
> Harold