Thread: wiring question

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I would like to know what, if any, shut down systems you guys are using for electric fuel pumps? I would like mine to shut down if the engine dies. I have considered using the inertia switch from a Ford and also wiring a relay into my stator. Ford alternator with external reg. I am not sure the 8-9 volts from the stator is enough or if that constant load on the stator would be damaging. A prime button isn't a problem.

You might consider a oil interupter switch. All it is, is a oil pressure switch that will close at 2 lb pressure and remain that way as long as the engine is running, and maintaining pressure. As soon as the engine is shut off or quits and the pressure drops the power is cut off. It will have two contact screws so you can hook into a electrical feed line, (power source). I would use it with a 30 amp relay, (Hella, Bosch or some similar make) and control the relay with it. Which in turn, controls the fuel pump. That way you won't burn out the points in the switch. Most automotive parts stores will have it, or can get it, they are used on industrial engine a lot, to control the hour meters. Simple and easy to hook up and trouble shoot, if it were to be necessary in the future. Sniper

Originally Posted by Sniper

You might consider a oil interupter switch. All it is, is a oil pressure switch that will close at 2 lb pressure and remain that way as long as the engine is running, and maintaining pressure. As soon as the engine is shut off or quits and the pressure drops the power is cut off. It will have two contact screws so you can hook into a electrical feed line, (power source). I would use it with a 30 amp relay, (Hella, Bosch or some similar make) and control the relay with it. Which in turn, controls the fuel pump. That way you won't burn out the points in the switch. Most automotive parts stores will have it, or can get it, they are used on industrial engine a lot, to control the hour meters. Simple and easy to hook up and trouble shoot, if it were to be necessary in the future. Sniper

I hadn't thought of that. I should be able to adapt one from a GM car. Thanks, I knew there was a simple answer.

Originally Posted by Sniper

You might consider a oil interupter switch. All it is, is a oil pressure switch that will close at 2 lb pressure and remain that way as long as the engine is running, and maintaining pressure. As soon as the engine is shut off or quits and the pressure drops the power is cut off. It will have two contact screws so you can hook into a electrical feed line, (power source). I would use it with a 30 amp relay, (Hella, Bosch or some similar make) and control the relay with it. Which in turn, controls the fuel pump. That way you won't burn out the points in the switch. Most automotive parts stores will have it, or can get it, they are used on industrial engine a lot, to control the hour meters. Simple and easy to hook up and trouble shoot, if it were to be necessary in the future. Sniper

Summit used to have one - this is Speedway's version
http://www.speedwaymotors.com/p/4774...0pump%20switch

A Chevy Vortec 350 truck engine has an oil pressure sender that has two circuits, one is a fuel pump open/close circuit that controls a relay for the fuel pump. We use this quite often. This sender screws into the regular sender hole at the back of the block. It's cheap. As I remember, you can also buy the pigtail connector that mates to the sender.

mike in tucson

You can pick up the oil pressure shut down switch at marine dealers too. Most I/O and inboard boat motors have them to shut down the engine if oil pressure drops. Downside is that the switches do fail, and prevent the engine from starting, but that is a somewhat remote possibility.

Don

Originally Posted by IC2

Summit used to have one - this is Speedway's version
http://www.speedwaymotors.com/p/4774...0pump%20switch

That looks like a good one, shuts down at 12 psi.
I wouldn't be able to use it on my 390, I don't think it can make 12 psi.lol

Originally Posted by willowbilly3

That looks like a good one, shuts down at 12 psi.
I wouldn't be able to use it on my 390, I don't think it can make 12 psi.lol

I found the Summit version p/n SUM-G1438 - and I happen to have an extra new/unused one. It shuts down at 7psig. PM me if your interested - I'll never use it.

Originally Posted by IC2

I found the Summit version p/n SUM-G1438 - and I happen to have an extra new/unused one. It shuts down at 7psig. PM me if your interested - I'll never use it.

Thanks for the offer, pmed you.
The 390 I joked about is my daily driver. My rod has a somewhat healthier 260 but knowing old Fords it might not have much more than that at a hot idle.

I used GM Part number 3986857 Fuel pump safety switch on my 350.