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need help....strange fuel pump noise


redpino

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I recently got a 88 n/a 300zx. The last week i discovered a strange noise coming from the back of it, i got more closer and realize it was the fuel pump, this noise is always there, even if the car its off. i want to know if this is normal or if it is time for a new one.

i will appreciate any help of you guys....tanks!!:-)

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Why would you get a new pump. There may be nothing wrong with it, could be the wiring. But it sure would be strange if the pump ran all the time and didnt kill the battery!?!?

 

 

So the fuel pump is one when the car is off? Dose your Battery Die. Its not the Power attenna trying to go up or down? Get a NEW ONE ANYWAY!!! newer is better :wink:
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hi guys....

well, im sure is not the antenna because i took off the fuel pump fuse to see what happened and the noise stopped the same way if i disconnect the battery....in fact, since i found the noise, i always leave disconnected the battery.....

what should i do?? tanks!!

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Well if its Pump then yeah Wiring issue. Perhaps check first the grounds although I think that would cause it to not turn on at all. Uhm but if you go to my Album I have the wiring Diagrams for the 300zx so theres a Realy. That could be stuck Open, and theres a Modual I beleive one sec... looks at Diag ok here you go

 

FPR (fuel pump relay)

 

Black on one side to Body Ground (so any problems just take new wire toa ground.)

Yellow/Black to Pin 20 (Ecu labeled on the connectors)

Blue/White to that Fuse you pull and to Fuel pump itself

Black on other side to PIN 108 and to Fuel pump itself.

 

So If that helps ya there you go. Has to be something is leaving the ECU on or soemthing to that effect. Cause if ignition is truely off then the Pump should have no Power. another thing is Take out that FUSE 10A for the Fuel Pump. then go to battery with it connected. Buy a Ohm - Volt meter. and check voltage hold it there for at least a minute and see how fast VOltage drops

 

Example: If you read say 12.85V but after a Minute your close to 12v or under 12V then something is drawing power. Ie then you might want to look at the ignition perhaps its stuck open. Or the Main Relay which go to pins 9 (red wire), 35 (Black White), and 2 that are brown that join and go to the fuseable link box by the battery in the engine bay. Something has to be fugged up and On.. hehe. I would have to go through Testing proceedure in online manuals to see if any of those are supposed to be active while key is off.. Going out for Breakfast I'll try to look for you in a bit. But basically if you start checking Draw on those wires and if you pull one the draw Stops then you've found your culprit.

Its an Open somewhere

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