Overactive Fuel Pump?

[Ankana]

While cleaning my garage, I noticed that the fuel pump on my 00 Accord was coming on every five or ten minutes. Is my pump/relay bad? I have no fuel leaks that I am aware of. This certainly isn't normal, is it?

[deaz]

Is that what that constant on-off humming noise is that I keep hearing all the time?

[mpumas]

You say it is coming on with the key off? If so, you probably have a shorted main relay.

[Ankana]

Here I have someone telling me this is a defect, yet there is somone else out there who's car does the same thing? ...Ponderous...
Main relay eh?
Found this:
http://techauto.tripod.com/
gives some usefull information about troubleshooting and even repairing solder joints on the relay board, but doesn't address what might be causing that particular relay to be causing the fuel pump to engage without the key in the ignition. Sounds as if it may be a faulty ignition switch? Anyone have any advice on that?

[mpumas]

With the key removed, the fuel pump should not pressurize the system. The fuel pump comes on when the key is turned on because voltage from the ignition activates the main relay which in turn activates the fuel pump relay which turns on the fuel pump. So why is there voltage on the circuit that comes from the ignition switch with the key in the off position. It could be the ignition switch or it could be coming from a device that uses both ignition switch power and allways hot power. A way to check if it is the ignition switch is to remove fuse no. 2 (15A) and see if the voltage goes away. (You need a voltmeter to see what is really happening) If you still have voltage on the yel/blk at the main relay, try disconnecting the alternator, then cooling fan timer unit or ifan thqth tvoltage vcooling mobvefemo

[Ankana]

Thanks Pumas, I had the same problem in my 72 Torino Sport. Of course then it meant that I had forotten to flip the toggle switch. (my own flavor of an anti-theft system/upgrade/hot rod wannabe hack job) -sorry, off on a tangent- So normally,
(no key)=(no power to main relay)=(no power to fuel pump)=(shouldn't be repressurizing)

[mpumas]

no key=no power to main relay--is not really true. There is power to the relay but only to one of the contacts on one of the relays. When the key is turned on, voltage is applied to the coil of one of the relays which then sends voltage to the ECU and activates the fuel pump relay. Honda uses a lot of relays like this so that current through the ignition switch is minimized. Any further progress on a solution to your problem?

[Ankana]

Thanks again, Lots of good information. No progress yet, my family, commute, and my second job takes up all of my time during the week. I hope to get to it this weekend. I'll post the results of my efforts, unless I screw it up, in which case, I'll take it to the dealer and you'll never hear about it.

[mpumas]

If you take it the dealer, we want to know what the dealer found to fix the problem. We are interested in solving problems here no matter how.

[Ankana]

I was only kidding. I don't really expect I'll screw it up.