Fuel Pump electrical problem

[10cjennings]

While driving my 73 240z began to sputter and die, s if it was running out of gas. I checked and the fuel pump (it's an electric inline pump) was definitely not turning on. Towed the car home, lifted the back end up and after the key was in the ignition turned to where the fuel pump SHOULD work for 2-3 minutes it all of a sudden appeared to have turned the pump on (it was making it's standard noise), but still, no fuel was getting to the carbs. I hooked a Voltmeter up to the fuel pump wires and even though the pump would make noise, and I even saw a small spark when I hooked up the voltmeter it read no volts (I know it was working, read 12V on my car battery). So I pulled the fuel line directly off the pump, ran the pump and it is definitely not pumping gas through its self. I pulled the pump off the car, attached it to another car battery, and then it pumped fuel. So basically the pump works, the fuel lines/filter aren't clogged, and it appears as if the pump is not getting power (though it makes its "whirring" noise). So what I need to do is work my way backwards up the electrical system tryng to find the bad connection but I have no idea where to start. It's a '73 so I'm pretty sure there isn't a fuse for the fuel pump in the fuse box, and I have no idea what wiring behind the dash correlates to the pump. Any ideas on what I should be looking for to identify the fuel pump electrical parts, or other things I should check to narrow down the options?

Thanks,

Chris J.

EDIT: So I put the pump back in, turned the key and for whatever reason it is now working agian (and getting a voltage reading on the pump wires). I'm sure whatever casued the problem will resurface soon, so I'd still like to know how to track down the fuel pump wiring on this car and figure out where the connection was lost.

[IdahoKidd]

It sounds like a line blockage in the tank, somehow fuel isn't getting to the pump. Your post is a bit disjointed, but the way I read it was that when you took the pump off and hooked it up to a different battery, and presumably a different fuel source it worked. You also said it made noise "like it worked" when hooked up to your own car. If it makes noise, works on a different car, it certainly sounds like a fuel pickup problem and not an electrical problem. These cars, especially when they have sat for some time, get nasty in the gas tanks and it may need cleaned out. Pull the inspection cover over the fuel gauge sender and then pull the fuel gauge sender and look in with a flashlight. (cover is in right rear of the hatch, under the carpet, held in by two screws. Look to see if it is shiny and or if it is corroded and looks like peanut butter.