Holley efi (model 502 analog system)

[Tom Cloud]

Here are some notes about the way the Holley ProJection system
works.  I'm slowly reverse-engineering it so that I'm not
left stranded (like I am right now ..... with an injector
that doesn't work and don't know where to get another $69 from
Super Shops).

I've heard that a standard Bosch injector works but I don't
know if that's true or what part number.  If someone knows any
more info on this, please let me know (I need one yesterday !!).

The injector measures 1.8 ohms resistance (well, the other one
measured 7.4 ohms, 332 ohms, 1.5 ohms, open circuit, etc, etc)

Measured the injector pulse -- it's .7 to 1 millisecond low
(injectors tied to +12) as a constant pulse width and the
rep rate varies with RPM, TPS and temp.

An interesting observation:  the fuel pump control line, instead
of just being a DC low, is a pulse train with a 78% (low)
duty cycle of 225 microseconds with a high pulse of 50 microS.
Weird!!  I have it driving a relay, so it's not coming from the commutator
of the pump -- the ProJection is supposed to lower the joltage
to the pump at low rpm's, so I guess this is how they do it
(sorta a "switcher"  ;-)


    ========================================================

Below is a list of all the active devices (not counting diodes)
on the PCB.  The ones I haven't found any data on are marked "**"
Question .... do you recognize the part numbers of the ones I've
marked "**"   ??


        2N2907A  (PNP)

        2N2222A  (NPN)

        2N7000  (N-ch TMOS)

        CA3240 (8-pin DIP) [dual Bi-MOS wide band op-amp .. Harris]

        CA3290E (8-pin DIP) [dual Bi-MOS op-amp .. Harris]

**      CS453 (TO-220) [5 pins]

        LF398 (8-pin DIP) [sample & hold]

**      LM2917 (8-pin DIP)

        LM2930T-8 (TO-220) [lo-dropout V-regulator 8V]

        MC14046 [PLL]

**      MJE-295 (TO-220) [has an "ST" logo]

**      MTP-305 (TO-220) [has an "ST" logo]

**      RC4200N (8-pin DIP)



Tom Cloud

     I took an IQ test and the results were negative