Noise (humming) coming from under back seat - Honda Prelude Forum

FamilyPrelude · 06-14-2009, 09:03 PM

When I shut my car off sometimes, I still hear something running.
Seems like it might be coming from under rear seat.

Is this the fuel pump? Why would it be running after the car is shut off.

Thanks for any info.

danfau07 · 06-15-2009, 04:12 AM

have someone sit in the car, go to the gas filler tube and open it. have the person turn the key right before starting. if its the same noise, its fuel pump. as far as continue running, no clue. maybe short. hope someone else has more input.

FamilyPrelude · 06-16-2009, 08:03 PM

OK,
I have an update, after I unscrew the fuel cap the noise goes away, like it relieves the pressure on the fuel pump.
Is this normal, or is my fuel pump going out.

Anyone had this problem?

daviddon · 06-18-2009, 02:29 PM

I'm going to take a wild guess and say one of two things is happening.
1) Your Fuel tank is not breathing properly and the pump is accumulating reverse pressure - causing the fuel flow to reverse into the tank (therein spinning the furl pump backwards - Until you relieve the pressure in the cap (which is likely the cause of the problem )
Replace the fuel filler cap with one that breathes properly.
or
2) the Fuel pump has a freaky short in it and needs to be replaced. I'm thinking that the timing of the Fuel filler cap vent release might be incidental and unrelated.
* it could also be a wiring ground fault so if you are replacing the fuel pump - have it tested - They are not very hard to remove - access it through the trunk and it only takes a few simple tools and some time.

I'm not there to look at it, but that's my best guess.
DjD