Re: V8 '165 harness modifications

[Brent Obermiller <ober_b@sssnet.com>]

SPECTRO COATING CORP. wrote:
> 
> > | Why is there an oil pressure switch in parallel with the fuel pump relay
> outp
> > | ut?  Does the relay prime the pump, turn off and then when oil pressure
> is bu
> > | ilt up enough the pump is turned back on by the oil switch and no longer
> the
> > | relay?   If I have this wrong, could someone please explain to me the
> sequenc
> > | e of events?
> 
> Because GM doesn't use a impact switch on the fuel pump (Ford does).
> 
> The relay is energized from the ecm on startup to pressurize the system for
> a quick start.
> 
> At that point the oil pressure switch takes over and supplies power.
> 
> If the engine should lose oil pressure - either by mechanical failure or as
> in the event of an roll over - it shuts down the fuel pump.
> 
> Just a another method to protect the occupants in a crash.
> 
> ----------------------------------------------------------------------------
I eliminated the pressure switch from my 7747 setup, the relay stays
closed as long as there's a tach signal (i.e. engine is running; small
safety considerations.) However, the wires through the pressure switch
are a heavier gauge wire.
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