Fuel pump making noise/staying on after turn off

BigSlappy

Member

Sep 4, 2022

73

14

18

Buffalo, New York

Apr 16, 2023

#1

• Apr 16, 2023

• #1

My fuel pump sounds like it stays on when the car is off completely. Theres also a high pitch sounding noise coming from it too. I noticed that if i slam the door a couple times to kinda shake the car, itll go off. Its a new fuel pump in the car. I was thinking maybe electrical issue, but i have no clue where to start for it. I have a video of the sound when its off from both the fuel lines under the hood and from the trunk. Theres no radio on or anything, all of that buzzing is coming from the tank

Heres the video i took of the noise:

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

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Claremore, OK

Apr 16, 2023

#2

• Apr 16, 2023

• #2

So when you turn the ignition off there the pump is supposed to loose 12V. Possibly three options here of which are ignition switch, the fuel pump relay, or the capacitors in the ECU crapped the bed. This is assuming the wiring in the car is stock.

 

BigSlappy

Member

Sep 4, 2022

73

14

18

Buffalo, New York

Apr 16, 2023

#3

• Apr 16, 2023

• #3

AeroCoupe said:

So when you turn the ignition off there the pump is supposed to loose 12V. Possibly three options here of which are ignition switch, the fuel pump relay, or the capacitors in the ECU crapped the bed. This is assuming the wiring in the car is stock.

Click to expand...

From what you said, it could definitely be the fuel pump relay. Ill google a couple things and figure out what i can get done during a rainy day.

 

BigSlappy

Member

Sep 4, 2022

73

14

18

Buffalo, New York

Apr 20, 2023

#4

• Apr 20, 2023

• #4

So, I tried hitting the ecu a couple times to see if that would be it, no luck on that. I tried shutting the doors a couple times on both sides but yet no luck either. Since I couldnt turn it off like i usually do, I unplugged the battery. It turned off, but as soon as I plugged the battery back in, it turned right back on. You guys think its probably it not losing the 12v?

 

Mstng93SSP

You have a nice rear end there Dave.

15 Year Member

Nov 29, 1999

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Mililani, Hawaii

Apr 20, 2023

#5

• Apr 20, 2023

• #5

Check the fuel pump relay. Sounds like it is stuck.

 

Reactions: General karthief

BigSlappy

Member

Sep 4, 2022

73

14

18

Buffalo, New York

Apr 21, 2023

#6

• Apr 21, 2023

• #6

Mstng93SSP said:

Check the fuel pump relay. Sounds like it is stuck.

Click to expand...

This was the issue. I had a little drive and turned the car off. The fuel pump turned off as soon as my hand touched the relay. I shall be buying a new relay and hope nothing sets on fire under my butt while driving.

 

Reactions: General karthief and Mstng93SSP