73 240z Aftermarket Fuel Pump and starter electirical question

[mr_han_solo]

Hello,

I purchased my first Z car yesterday and while it may be kind of rough, the guy told me that it was running when he parked it. Unfortunately that was two years ago and it looks like he cut the cables when he took the battery out, or the battery was stolen and all of the cables were cut. I installed new terminals today and I am just trying to see if I can get the car to start. Unfortunately, it looks like the car was replaced with an after market electric fuel pump and I have no idea how it’s supposed to work. I have some questions and my hypothesis, and I have presented it with pictures and a diagram. I am just wanting some conformation that what I am presenting is correct or some suggestions if I am wrong.

First under the dash:

As you can see there is a switch to turn the electric pump on and off. The red wire going outside the car is A, whole the other switch wire goes into the console.

Now onto the engine bay:

Here you can see where A comes up and has been cut off. My hypothesis is that it needs to be wired onto A? which goes into the fuel pump. B? Is the black wire from the fuel pump and I'm guessing it gets screwed onto the body as a ground.

Now I will ask about the fuel lines. 1 comes from a steel line on the frame rail and my guess is that it goes into the fuel pump. Line 2 out of the fuel pump should go to line 3 which goes to the regulator. From the regulator line 3 goes into another steel line which goes to the carbs. Line 4 is the return line from the carbs and goes back into another steel line on the frame rail. Just wanting to make sure all of this is correct.

Here you can see the + and - Battery cables I'm guessing that ?2 is the red line from the switch that went into the console and dash. I suppose it should be wired directly to the battery.

I have no idea what the connector ?1 is. I was hoping someone here could fill me in on it and tell me if there is anything else I need to hook up to get the car going.

Thanks,

Han

[Stanley]

Congratulations, I guess. Check out the search feature - there's a lot of good stuff on this site about starting a car that's been sitting a long time. Stuff like draining the tank, changing the old filters and hoses. Maybe it's better it didn't start right off. Don't want to go for a drive if the brakes don't work, or there's no oil, for example. I'm thinking the guy lied about some stuff, or maybe he didn't remember. Could have been twenty years instead of two. Alcohol's a hell of a drug. Stealing old batteries seems like a hard way to make a living.

Those wires don't look too good. Maybe you could find a junked z somewhere and scrounge some wiring harnesses off that. You can download the factory service manual (FSM) and some wiring diagrams. Someone posted some color-coded wiring diagrams recently. You could get a mechanical fuel pump at autozone or somewhere and hook that up - might be easier.

Gotta start somewhere....

[beermanpete]

The white wire (?1) with the connector is the main feed to the car. It connects to the positive battery cable at the starter motor through a fusible link.

The red wire might have been added as it is not in the factory wiring diagram. Try tracing it through to see where is connects at the other end.

Your hypothesis about the fuel pump wiring sounds right. The 73 came with an electric fuel pump from the factory (it was in the back near the fuel tank) so there is a wire for it already that turns on/off with the ignition switch. Look for a medium size (12 gauge?) blue wire near the fuse box with an in-line fuse holder.

You are also correct about the fuel lines. The fuel line from the tank to the pump is larger (5/16" ). The return is smaller (3/16"). The line from the pump to the carbs is 1/4". Set the regulator to 3 1/2 PSI.

You can get the factory service manual for free at XenonS30. The wiring section will help you sort out the details.