Re: Can you/should you "hard wire" fuel-pump"???

- M
- Mark Olson
  
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posted
20 years ago

Sat, Aug 30, 2003 1:49 AM

I was wondering if I could maybe "hard wire" the pump, so that it is
> always running whenever the ignition is on. My understanding is that > if I just left the key on, but didn't start the engine, the fuel > pressure regulator would open and allow excess fuel to bleed off into > the return line. I suppose the only downside to this, is that if I > ever lost oil-pressure, the engine would still run and destroy itself. > Then again, I would probably still get the warning-light on the IPC, > so I might at least notice it... > > What do you guys think? Is my theory correct??? Should I try and > hard-wire the pump? Would there be an ill-effects???

Do you know why cars with electric fuel pumps have inertia switches to turn them off in case of a crash or rollover? Also, oil pressure switches and crank pulse sensors don't just protect the engine, they protect you from the risk of fire from spilled fuel if the car turns over, etc.

- R
- Robert Hancock
  
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posted
20 years ago

Sat, Aug 30, 2003 3:29 AM

Not a good idea, in the event of a collision and fuel line breakage, there will be nothing to stop the fuel being pumped out.

Aren't you replacing the ECM with the other one? You should be able to hook up the fuel pump relay output from the replacement ECM..

- S
- sdlomi
  
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posted
20 years ago

Fri, Sep 12, 2003 10:56 AM

Joe, you've got some good replies and some safety ideas. Should be simple enough to put a 'teed-in' o/p switch that would maintain the circuit as long as the engine had oil pressure(running). You'd just hafta install a 'momentary' switch--like an old push-button starter switch--to complete the circuit for starting before there was oil pressure(no o/p when not running, altho' spinning over does create some pressure, but maybe not enough to complete the f/p circuit at startup) to maintain the contact after you release the push-button sw. HTH & good luck. s

- P
- PA-ter
  
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posted
20 years ago

Mon, Sep 15, 2003 12:34 AM

Did this on a S-10 that I v-8ed with a 350 small block & a carb. Used the factory in-tank pump, it fed the TBI on the original 2.5 that used

14 lb. of pressure, thru a regulator to get my 7 lbs. at the carb. Retained everything stock & grounded the exiter wire (green)at the relay that normally got it's signal from the ECM. I'm gonna think you could run the wire thru an oil pressure and/or an inertia switch to effect saftey concerns, no computor required.