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I have a 81 280zx n/t. After I bought it, I discovered that one of the previous owners had installed a switch inside the car that could cut the power to the fuel pump. Recently, I turned off the car and the fuel pump kept running. Next thing I knew, the battery was dead. Anyway, I was wondering if anyone else has a switch like this or knows how I can remove this.

Thanks
 

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The previous owner was trying to rig up a fix for a problem. Sounds like the relay for the fuel pump was bad or the wire from the oil pressure sensor (part of the safety switch to shut off pump in case of accident). Get a factory service manual, go to the body electrical and engine fuel sections and follow the wiring diagrams.
I am not sure about the ZX, but on the Z's with the key in the on position, the fuel pump is off. It will only run while the key is in the start position.
 

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I was told that this switch was installed as a sort of 'Anti theft' device. So that I could flip the switch and if someone tried to steal my car, the engine would stall because no fuel was getting to the engine. I checked my relays and both seem fine but the relay in the bottom left corner [standing over it] didn't have a terminal in the closest slot to the engine. It has run fine for the past 8 months like this, the problem started today.
 

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I am building a modified 71, i put a eletronic fuel pump on my car. The switch is used in case of an accident, your car wont shut off, and fuel will continue to flow. The switch is so you can shut it off. Just leave it on, you shouldnt have a problem
 

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What to check.

Your car has three individual relays controlling the fuel pump. Fuel Pump Relay # 1 is under the passengers side dash panel above the fuse box. FPR # 2 and FPR # 3 are in the relay container on the passengers side inner fender well in front of the strut tower. They are the two relays closest to the fender and the strut tower.

The first thing to do is follow the wires from the user installed switch and tell us where they go AND what colour the wire is in the harness they are spliced into.

Power to the fuel pump comes directly from the fusible links to the white / black wire at FPR # 1 then through the contacts and out the green wire to the fuel pump.

The green / white and black wires at FPR # 1 controls the coil in the relay.

With the key "off" you should have 0 volts between these two wires(green / white and black). You should have +12 volts at the white / black wire and body ground. You should have 0 volts at the green wire. If you have +12 volts at the green wire with the key "off" then the contacts are welded "closed" inside FPR # 1.

Wayne Monteath
Masham, Quebec.
 
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