1970 240z electric fuel pump question

[Phengvang18]

Hello all,

 

I have been reading several old threads on installing the electric fuel pump but I am stump on a few things.

 

To provide you a little background, the previous owner of my 240z had installed a electric fuel pump into the car but did not use the factory wires that were available for use in the installation of a electric fuel pump and I would like to revert it back using these supplied wires that exist in the harness.

it appears the previous owner ran his own wire from the fuel pump into this relay.

now the reason why I would also like to revert back to using the factory electrical wires that were provide for the electric fuel pump installation is because I plan on upgrading my alternator and using Dave’s alternator adaptor. In the picture above, what could the blue wire that I’m holding be connecting to? Ignition? 
 

in regards to using the old factory wires that were provided in the harness for the installation of a electric fuel pump,  Where do I connect the green wire to in the “T” connector in the center console for the electric fuel pump? 
 

 

In the picture provided below, does this wire connect into the new relay I plan to use for the electric fuel pump ? If so, my question is where Does the green wire in behind the center console in the “T” connector connect to? 

 

I hope my description makes sense, please let me know if not, and I can take more photos. 

[SteveJ]

1 hour ago, Phengvang18 said:

Hello all,

 

I have been reading several old threads on installing the electric fuel pump but I am stump on a few things.

 

To provide you a little background, the previous owner of my 240z had installed a electric fuel pump into the car but did not use the factory wires that were available for use in the installation of a electric fuel pump and I would like to revert it back using these supplied wires that exist in the harness.

it appears the previous owner ran his own wire from the fuel pump into this relay.

now the reason why I would also like to revert back to using the factory electrical wires that were provide for the electric fuel pump installation is because I plan on upgrading my alternator and using Dave’s alternator adaptor. In the picture above, what could the blue wire that I’m holding be connecting to? Ignition? 

In regard to the wiring the IPO put in, the blue wire is the power for the fuel pump relay coil. It's connected to the yellow wire that is shown in the wiring diagram between the voltage regulator and alternator. The blue wire runs from the yellow wire to the 85 or 86 pin of the relay. The curly wire runs between the 86 or 85 pin (whichever the blue wire is not on) to ground. The black/red wire is the power for the fuel pump. It is going to pin 30 or 87. The white wire is going from the 87 or 30 pin and on back to the fuel pump. With the way it is wired, if the black/red wire came off the relay while the car is running, it could cause an electrical fire since there is not a fuse between the alternator and the relay.

As you seem to have figured out, the blue wire will go away after modifying the electrical system for an internally regulated alternator.

[Blitzed]

Hi All,

Searched "Help Me" but came up short the specific answer. 73 240Z non fuel pump version. I'm installing a fuel pump and stumped on the factory wiring config at console.

Black and Green wires at the tank - Wires are there, all good

Black/ white and green under the console - Found them, see pic

The Black / white and green connector has never been connected to anything in the harness. Looks brand new.  

The only other connector not connected (same style 2 pin connector ) has a black /yellow and red wire (background of pic) and appear to loop to the fuse box. 

Could just put them together and wait for smoke and flames :)

Need a confirmation on this connection or another location.

Thank you. 

[Zed Head]

1 hour ago, Blitzed said:

Could just put them together and wait for smoke and flames 🙂

Meter.  Test light.

What you need might be in this document.

 

[Blitzed]

Hello Zed Head,

Thanks for the info but did not satisfy the question. Found the info on the second connector, fog lights. Will not put them together :) 

So anyone who has added /installed a fuel pump to a 240 (not previously installed), please respond. 

Found the connecter and proper wires at the console. The connector is not plugged into another terminal. Where does it connect?  No power with key in start position as it is a lose connection.

Thanks you

[SteveJ]

The green is usually related to the black/white. There is one green that is downstream of the fuse for the black/white in the fuse box. There is another green that branches off the black/white for the fuel pump.

So, how can you tell which green wire this may be?

1. Pull the middle fuse on the left side of the fuse box.
2. Set your meter to continuity.
3. Check each wire for continuity at the connector with the black/white and green wires to the right side of the middle fuse. See photo.
4. For each wire that did not have continuity with the fuse box, check again but with the left side of the middle fuse.

If the wires had continuity with the right side of the fuse, that means they are downstream of the ignition fuse.

If the wires had continuity with the left side of the fuse, that means they are part of the circuit that feeds the fuses for the ignition fuse and fuel pump.

Post the results of your test, and let's continue from there.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

[cgsheen1]

8 hours ago, Blitzed said:

 

So anyone who has added /installed a fuel pump to a 240 (not previously installed), please respond. 

Found the connecter and proper wires at the console. The connector is not plugged into another terminal. Where does it connect?  No power with key in start position as it is a lose connection.

Thanks you

You're on the right track. You need the companion connector for the 2-pin B/W - G. You can use the B/W (which is battery voltage at IGN ON) to power the fuel pump but you need some kind of "safety". You don't want the fuel pump to keep pumping in a collision where a fuel line might be damaged. I use an inertia switch - very common these days look on Amazon (or anywhere) - as my "safety" (circuit interrupter) between the B/W and the G wires. It can actually be as simple as that. B/W -> Inertia Switch mounted to steel of chassis -> Green, connect Green and Black near fuel tank to pump.

Find a used mating connector and make-do, or you can buy one new from vintageconnections.com. Or just replace the stock connector with the ones in this kit:

Oh, you'll want to  mount this switch where you have access to it to reset it if you ever need to (it will break the connection if it "senses impact" but can be reset by pressing the red button...)

Edited August 2, 2021 by cgsheen1

[Blitzed]

Hi cgsheen1,

Thank you for the response. So in the simplest answer yes or no. 

On a non factory fuel pump 240z. Did Nissan just run the wires and not complete the connection to the ignition? Lose connector at the console. 

If not complete, did they provide another factory connector at the console to plug into or do I need to run additional wires to the ignition to complete the circuit and power the pump? have a FSM but wiring diagrams are a mystery to me.

Thanks for the help and safety advise. Will purchase the switch.  

 

 

[SteveJ]

21 minutes ago, Blitzed said:

Hi cgsheen1,

Thank you for the response. So in the simplest answer yes or no. 

On a non factory fuel pump 240z. Did Nissan just run the wires and not complete the connection to the ignition? Lose connector at the console. 

If not complete, did they provide another factory connector at the console to plug into or do I need to run additional wires to the ignition to complete the circuit and power the pump? have a FSM but wiring diagrams are a mystery to me.

Thanks for the help and safety advise. Will purchase the switch.  

 

 

There is wiring in place for an electric fuel pump. Follow what I posted, and we can help you. I haven't messed around with the electric fuel pump wiring on the 240Z because my 240Z has the modification that Nissan designed for that year.

However, I do understand the FSM, and I'm trying to guide you on how to figure out how to wire it in. Please go back and read post #6.

[Zed Head]

SteveJ will get you where you want to be but there are some things in that document I posted that might be important.  Apparently, not all 73"s are guaranteed to be the same.

[Zed Head]

Your system might be incomplete.  

[Blitzed]

Hi All,

See relay pic. Only four relays on the right side kick. Car is documented as 73. Had the square rear sway bar mounts on the sub (no bar), so would assume late production.

Thank you,