Couldn't find anything in a site search or a google search so I thought I'd ask you guys and see if anyone else has experienced this. We just bought a '98 Accord (3L v6) and noticed that, even after the engine had been off for quite some time (2-3 hours) the fuel pump would kick on for a few seconds once every few minutes. While I've had vehicles in the past that would do this immediately after shutting the engine off for the fuel return, never had one do it consistently well after being shut off. I assume its trying to maintain prime / pressure on the line, but is this normal or do I have a relay / solenoid stuck in the On position so it still runs when the key is off??? Thanks in advance for any help you can provide!

 

I think you might be hearing one of the Evaporative controls, the 2-way valve opens if the pressure in the gas tank rises, and vents the fumes to the canister.
They can make a humming noise.
This condition usually happens in warmer weather.

You could also unplug the main relay under the dash, to remove power from the fuel pump circuit and see if the noise still occurs.