electric fuel pump

[puddle jumper]

What do boat manufactures do for auto shut off for electric fuel pumps in case of an emergency. Example autos have an auto shut off in case of an
some sort accident.

 

[PondTunes]

Re: electric fuel pump

I don't believe there are any fuel shutoff safety switches. I would think theres a lot of bouncing and banging around possible on a boat that could trip a typical shock sensor. There is the lanyard that should be hooked to the driver of the boat in case they were slung out of the boat. Once the lanyard was pulled loose it would kill then engine.

 

[tommays]

Re: electric fuel pump

Marine electric fuel pumps are controled buy the motor running with an oil pressure switch or some other type of circut that shuts it OFF if the motor stops running


Tommays

 

[Silvertip]

Re: electric fuel pump

Oil pressure switch on four strokes or the ECM can also detect if the engine is not running -- no tach pulses or no crankshaft position sensor input = no engine rpm.

 

[puddle jumper]

Re: electric fuel pump

Thanks guys i didn't think of using an oil psi switch. We use them all the time on our welders. Hooking it up in a friends boat that has a mechanical pump now.

 

[Silvertip]

Re: electric fuel pump

You had best investigate this a little further if you are adding an electric pump to what was a mechanical system. Most electric pump systems have a return line to the tank. Without one, the pump runs against pressure which causes it to overheat and draw a large amount of current. The boat was designed with a mechanical pump fix it -- don't band-aid a factory design.

 

[tommays]

Re: electric fuel pump

All the carb V-6 and V-8 Mercs have used and electric fuel pump for a long TIME


There is No return line it is just designed to work with that system and keep the same 5 to 7 PSI fuel pressure as the mech pump



BUT it would be a lot better to just put in the simple mech fuel pump and go boating


Tommays

 

[QuadManiac]

Re: electric fuel pump

Return lines are typically for high pressure pumps used with fuel injection... the standard, old style, 3-10 psi electric pumps (like a Holley Red used on my VW powered turbo sandrail) do not usually require a return.

 

[puddle jumper]

Re: electric fuel pump

Hes got an old Volvo 6 cylinder and parts are getting hard to find up here.
A low psi fuel pump will work fine i just needed a way to shut the fuel pump off if the engine were to die.

 

[Silvertip]

Re: electric fuel pump

Then use an oil pressure switch to cut the pump if the engine should die. Holly makes an electric pump which is adjustable for pressure. Keep in mind that the pump would not run until the engine built oil pressure so it would likely have to be primed before starting. The fix for that is to use a relay that momentarily energizes the pump when the ignition is turned to the START position.

 

[Reel Poor]

Re: electric fuel pump

Here is a typical Mercruiser wiring diagram. Note the purple/yellow wire connected to the D terminal of the starter, this will supply voltage to the pump will cranking the engine. Once the engine starts the oil pressure switch will keep it running until the engine is shut off.

 

[puddle jumper]

Re: electric fuel pump

Boy cant cant get better than that. Even complete with a wiring diagram.
Now that makes life easy. All were waiting on is parts now.
Thanks again.