240 1991 humming from fuel pump or sending unit?

Hello, Yesterday I noticed that there is a "new" humming/buzzing sound coming from behind the rear passenger seat area. I assume that it may either be the gas pump or sending unit? Is it getting ready to go out? Is the filter getting old/dirty and causing one of the above to over work. Are either of these fairly easy to replace? How would I know which one to replace, should I do it soon or wait until the unit stops working or the buzzing drives me bats.

Reply to
jsegura525
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It's the fuel pump, there's nothing to hum in the sending unit. Does the humming go away when the tank is full? Usually what happens is the pre-pump in the tank or the hose connecting it fails and that causes cavitation in the main high pressure pump under the car which is the humming you hear. If this is not fixed, the expensive main pump will eventually fail. None of this is terribly hard to work on, if you can change a water pump you can change a fuel pump. Do it now, it would be silly to wait until it leaves you stranded, when the main pump fails you're suddenly dead in the water.

Reply to
James Sweet

Thank you for the reply....I have a couple of questions..please work with me here. The sound just started a couple of days ago, so I don't know if it hums on a full tank. I don't want to fill it up if I need to open it up to replace the pre- pump. So as I understand there are two pumps, the main one is on the outside of the fuel tank, and a pre-pump inside the tank? When I replace the pre-pump I understand that I first off remove the fuel tank and then open it up and replace the pre-pump. How do I drain the fuel to make it easier. Thanks again for your help. Joseph Segura

Reply to
jsegura525

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