Hey guys...I have noticed that when I run my truck for short times (such as starting and moving out of the garage and turning right off) the fuel pump will continue to run with the key off for quite some time. The first time I noticed it, I climbed under the truck to investigate the noise. When I put my hand on the lower fuel filter, I could feel vibrations, causing me to believe it's the fuel pump running. The truck is mostly stock and has no problems starting or running. When I hear the pump running, if start the truck back up and let it idle for 5 - 10 minutes and turn it off, the pump will no longer be running. I have heard it running for up to 15 minutes after I have moved it out of my garage. Any ideas on what might be going on here?

 

Iirc the relay is part of the cjb and is not serviceable.
I suspect it maybe the vacuum pump you hear, they sound simular and are knowen for this concern were pumps are not.
If it is the pump all I can think of is check for water leaks under dash comming from the windshield.

 

Thanks for the quick reply cheezit. I haven't noticed any water leaks under the dash as the carpets are always dry. Where would I find the vacuum pump and what would be the best way to figure out if that is in deed be whats running?

 

Under hood passengers side bolted to fender next to ac box. Put your hand on, or unplug it.

 

I will look into this tomorrow. If it turns out to be the vacuum pump, any suggestions on where to start to determine why it continues to run when the truck is off? If the truck would have been sitting for a week or so, should it maintain its vacuum?

 

Replace the vacuum pump if thats the sorce. It would maintain vacuum if the system is sealed

 

So after keeping my fingers crossed that it would be as simple as changing the vacuum pump, it looks like that is not the problem. I started the truck, let it run for about 30 seconds and shut it off. I could hear a pump running, so I quickly ran under the hood and removed the power to the vacuum pump and I could still hear the noise. I went under the drivers side of the truck and it sounds like the fuel pump is running. Here is a short video of what I hear: Keep in mind, this is with the key out and the truck not running. If I run the truck longer, say 5 minutes, then turn the key off, the pump doesn't continue to run.

 

Your video is set to private. Might want to check the settings.

 

Thanks for pointing that out...Hopefully you can see it now.

 

If it was me I would try the cheapest thing I could find. I would replace the fuel pump relay the under the hood in the fuse box. My thinking is that it could be going out and not releasing its contact in a timely manner. Normally they just stop working but its where I would start. EDIT: Could not find a relay for the fuel pump in the manual. I guess I'm giving you bad info. I'm interested now because I could have sworn I hear a corresponding click when the pump kicks off. Still going to go out a feel what one is energizing and see what its running and if theres any relation.