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Discussion Starter · #1 ·
Did any of you guys use the Ford emergency fuel pump shut off switch (the inertia-activated one)? I never installed one, but now that I'm getting closer to the end of my build, I'm wondering if I should put one in. Probably a good idea, but I don't recall seeing any posts on this.
 

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Discussion Starter · #4 ·
I don't have one from a donor car, so can I just pick up a new one from Ford? If so, what model and year is the best option? Or do some have complex harnesses that tie into the computer system?
 

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It's got it's pros and cons: http://www.ffcars.com/forums/68-road-racing-discussions/286040-fuel-pump-inertia-switch.html

Since Ford does it but many other makers don't, I speculate how much the liability lawyers got involved. Upside down, the fuel sock may likely suck air, carb or EFI, so the extreme case isn't necessarily the issue. Unfortunately, the oil pickup will also be sucking air, too.

The issue is really one where there's been a major intrusive impact that cut a fuel line and the pump is still running. Many times that kills the motor, especially on a manual trans car. After all, it was in gear but now is stopped. With EFI, check whether your system has an auto shut down relay in the system <----- The other guys answer. If the engine isn't turning over, no crank timing is detected, and the computer shuts down power to the pump. Most cars are set up this way.

So, there are other ways that can be used to handle it. Depends on exactly what the specific EFI system has, or how you set it up. It's good to consider the issue, especially since You're The Design Engineer.
 

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I initially installed one, and then removed it. Every time I did a hard launch, it would trigger the relay and the engine would die. Very disconcerting.
 

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Discussion Starter · #8 ·
I initially installed one, and then removed it. Every time I did a hard launch, it would trigger the relay and the engine would die. Very disconcerting.
Yeah, I heard about that problem, which was my initial reason for not putting one in. But then I got rear-ended in my Ford Edge a few months back, and it got me thinking about what would've happened in my Daytona, with no rear bumper and the gas tank acting as the "crumple zone". If the fuel line was to get cut, the thought of fuel spraying out into the back of the car is making me reconsider. I have a carb, not EFI, want to make sure the pump shuts off automatically if I'm knocked out.
 

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It doesn't require it's own wiring. You just put it inline with the power line for the fuel pump. When it trips it cuts the connection until reset.

Ask a junkyard for one, not much need to buy new here...

[edit]Mount it securely to the frame somewhere. I could see vibration setting it off, but I have 3,000 miles on my Coupe with no problem. Yes, I did test it when I installed it. :)
 

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FFCobra Master Craftsman
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I have a carb on mine too and added the cut off. I mounted mine next to the shifter just for easy access if it did trip. just hitting the side of the center consoule will trip it if needed too.



it is the red button of course. it does not need to go upside down to trip. the ball sits in a tapered hole so a good side hit will cause it to lift up and trip the cutoff.
 
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