Holley efi (model 502 analog system)

[Sandy]

Hey TOM, don't laugh, but I think that part of the schematic for the EFI
sytem is printed on the cover of the MSD Fuel system catalog. It is
obscured by a bunch of efi stuff, but I think that it is the same or
something similar to what you have. The catalog is the MSD Fuel management
catalog from 1993.

The CS453 is the 4amp peak/1amp hold hold driver from cherry.
The LM2917 is a frequency to voltage converter from National Semiconductor.
The MJE and MTP parts with the ST marking are SGS Thompson I think. These
are typically Motorola Part numbers, so check their web site.

I'm not sure what the RC4200 is.


Sandy


At 09:34 AM 8/21/97 -0500, you wrote:
>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
>
>