skunks 510

[datzenmike]

There is a Nissan relay with 5 terminals on it. Two of the terminals energize the coil and close a contact inside. The other three wires are one common and one each of ON or OFF depending if the relay is energized. Connect the ignition ON wire to one side of the coil and the other to the oil pressure sender which should be grounded because there is no oil pressure. Also run a wire from the ignition ON to the (OFF) position of the relay (this will be off because there is no oil pressure and the relay coil is energized and connected to the ON output. Connect the start output to the common terminal output on the relay that is connected to the fuel pump.

 

Get in and turn ignition ON:

Oil sender grounds the relay switching the power from the ignition to the non used ON position of the relay. Nothing happens.

 

Turn to START:

Start signal flows to the comm output and to the fuel pump.

 

Engine starts, key released:

Power from the start position stops but now there is oil pressure and the oil sender is no longer at ground so the relay opens and returns to the OFF position and ignition power now flows through to the comm output and to pump.

 

 

As long as there is oil pressure the relay is off and power flows to the pump until the ignition is turned off. If there was an accident and the engine stops the oil pressure would drop, energizing the relay and shutting off the fuel pump.

[skunk]

There is a Nissan relay with 5 terminals on it. Two of the terminals energize the coil and close a contact inside. The other three wires are one common and one each of ON or OFF depending if the relay is energized. Connect the ignition ON wire to one side of the coil and the other to the oil pressure sender which should be grounded because there is no oil pressure. Also run a wire from the ignition ON to the (OFF) position of the relay (this will be off because there is no oil pressure and the relay coil is energized and connected to the ON output. Connect the start output to the common terminal output on the relay that is connected to the fuel pump.

 

Get in and turn ignition ON:

Oil sender grounds the relay switching the power from the ignition to the non used ON position of the relay. Nothing happens.

 

Turn to START:

Start signal flows to the comm output and to the fuel pump.

 

Engine starts, key released:

Power from the start position stops but now there is oil pressure and the oil sender is no longer at ground so the relay opens and returns to the OFF position and ignition power now flows through to the comm output and to pump.

 

 

As long as there is oil pressure the relay is off and power flows to the pump until the ignition is turned off. If there was an accident and the engine stops the oil pressure would drop, energizing the relay and shutting off the fuel pump.

 

i think iv read this like 4 times, still dont get it.

I have a hard time processing words, im much better at visuals.

 

thanks for what looks to be great info, ill keep at it and figure it out

[Guest DatsuNoob]

Hmm, for my piaa lights wich are high wattage i used a 30, i think you could get away with a 20 at most.

 

My walbro 255 has 20A inline fuse required stamped on it. Not sure if that helps. Cant it just be ran off the original factory fuse location from the box? I'm gonna need some help with mine when you guys come up. I want to run a power shutoff switch (killswitch, whatever). What ga. wire does a guy run for something like this?? Sorry Kelly didnt mean to hi-jack.

[Jassifrass]

My walbro 255 has 20A inline fuse required stamped on it. Not sure if that helps.

It does help, im going to just use a 20

 

Cant it just be ran off the original factory fuse location from the box?

 

not sure what you mean, the original fuel pump is a manual pump thats run off the timing gear.

 

What ga. wire does a guy run for something like this?? Sorry Kelly didnt mean to hi-jack.

 

if i had to guess i would say 14, and dont worry about it. not really a hi-jack.

 

 

EDIT- damn it damn it damn it, i keep forgeting to check to see who im logged on as.

[datzenmike]

I would run as thick a wire as reasonable to reduce voltage drop. It's a long run to the tank and back by ground. Car makers use the smallest wire they can that does the job to save money. Pumps can supply almost any pressure. Diesel fuel pumps are in the thousands of PSI but no pump made can suck fuel up a hose that is above 31 feet tall. Suction losses should be reduced as much as possible by mounting the pump as low and close to the tank as is safe.

[skunk]

wait, so should i not be mounting my fuel pump in my engine bay? should i mount it down by the tank?

[Pumpkn210]

wait, so should i not be mounting my fuel pump in my engine bay? should i mount it down by the tank?

Depends on f its a push or a pull pump. The push pumps "Should" be as close to the tank as possable! If its a pull it can be anywhere, best to have it as low as possable. Easier to pump if gravity isnt a prollem!

[hang_510]

The push pumps "Should" be as close to the tank as possable!

yes!

 

and i have mine mounted on the firewall... :mellow:

[Pumpkn210]

yes!

 

and i have mine mounted on the firewall... :mellow:

 

Word, both of my fuel pumps are High! Both mounted on the pass strut tower. Not a big deal unless you run out of gas..... gotta prime errything!

[Skib]

mines mounted right next to the fuel tank.

bout 4in of hose from the tank to the pump :lol:

 

 

 

and its a Supra TT pump so it gets fuel movein :cool:

[Guest DatsuNoob]

My shitz is right under my tank, below the 2" baffle. Doesnt get any more gravity feed that that :lol:

[skunk]

so then eather way (push or pull) i could just mount that shit down by the tank and it will work. the more stuff i can get out of the engine bay the better.

[datzenmike]

Push? Pull??? ALL pumps have to do both. They have to draw fuel in before pushing it out. Pushing it is easy and can easily exceede thousands of PSI, like a pressure washer. Sucking fuel in is much different and relies on 14.7 PSI of air pressure at sea level. Any extra work like lifting the fuel higher than the tank reduces the output. A clogged filter or small or long fuel line will reduce this even further. NO PUMP MADE can lift water more than about 31 feet vertical. This is the height that 14.7 PSI will push against it if the pump produces a vacuum above it. Same thing with fuel pumps. Help it out by reducing the distance it has to suck fuel through a hose and lift above the fuel level in the tank. This is why EFI have pumps in the tank, well one of the reasons.

[skunk]

sounds like im putting the pump back by the tank, does it matter where i put the fuel pressure regulator?

[MicroMachinery]

I'd put the regulator in the engine compartment so that it's always easy to read/adjust.

[skunk]

well yeah, thats what i was wanting. just didnt know if it needed to be near the fuel pump.

[MicroMachinery]

Nah man, you'll be fine putting it in the engine compartment. Since you can't compress liquids, it doesn't matter if it's 10 inches or 10 feet away; you'll get the same readings.

 

There's your lesson in hydraulics for today. ;)

[skunk]

sweet, i should go get to it then.

[MicroMachinery]

We need pics of it running :cool:

[skunk]

yeah, i just got to get my matchbox working. going to start over and re do the wiring an hope i get spark this time.

[I'm BLUE]

I'd put the regulator in the engine compartment so that it's always easy to read/adjust.

 

+1 , that's what I did on my Z ,,, on the extra outlet just install a fuel pressure gauge :cool: ( That is if you have an (1) Fuel-Inlet , (2) Fuel-Outlet , and (3) Extra outlet :D )

[skunk]

i got some sexy new seats for my car, Thanks noob for the hook up. :D

they wont be put in anytime soon, im going to have to make somthing so they can mount in. Justin is going to come down with his welder some time an help me out.

[skunk]

dave these pics are for you, so you dont have to go through the whole thread

[Pumpkn210]

Thats the shit! And dont worry to much about rain. It takes alot of damn water to kill an engine ;)

 

Out The Hood FTW!

[skunk]

510 is not in portland, thanks to Ed i got a place to keep it till i can get her on the road.