Alright, please see my other post if you are not familiar with how slow my truck is.


If you're not a ls1tech surfer.... check this for explination:
If you're not a ls1tech surfer.... check this for explination:
https://ls1tech.com/forums/showt...t=207464&page=1


In short, I do 0-60 in 9.47 seconds -- slower than my mom's stock Tahoe.

Anyway... in addition to my slowness I've noticed some "bumps" at idle. I thought it was just a little bit of improper timing due to my stock pcm trying to leanr the cam. Well, it still does it and seems to have gotten even worse. Today when I got home, I got out to listen from the engine bay and noticed a high pitched whining from under the truck right as I stepped out. I said to my dad, "that sounds like the fuel pump." I got underneath and stuck my ear to the tank and sure enough, its coming from the gas tank. Very high pitched, annoying whine. Does this happen every now and then, or is my fuel pump just plain dieing?

Last time I listened for it (two days ago) I heard it whine as I switched the ignition on and it seemed to have that normal whine. Now its whining after I drive it! So, what is going on? Is this a sign the fuel pump is dieing? Can I blame those "bumps" at idle and my turtle-like speeds on a bad fuel pump?

What do you guys think?

My dad bought one for another vehicle one time and it was ungodly expensive. How much do they run for an oem pump? How much for an aftermarket and would that be neccasary?

 

Yes, a bad fuel pump can cause the engine to miss at idle speeds. An SES light should be lit so you can pull a code. Another cause of idle misses are faulty ignition system, spark plugs foulded gapped improperely,etc. Vacuum leaks or uneven cylinder pressure. I can't remember this accurate, but I do believe a fuel pump will whine excessively loud when it's about to go out, I think, not quite sure on that one though.
Hope I helped a little.
Philip S.

 

Thanks for the help man!

I'm hoping that this can be at least a little to blame for my super slow 0-60 time. Can anyone explain what's mechanically/electrically happening to make it whine?

Any more thoughts?

 

My pump sounds alot louder when my gas tank gets closer to empty. I think because the pump isn't submerged. Could this be what's happening?

Also, they will whine louder if your filter needs to be replaced.

 

i have seen dirty injectors cause the exact same thing you are experiencing. it cost about $100.00 from the dealer for them to clean them and is well wort it.

 

Hmmmm. Mine whines like a ***** and I have no idea what it is. It's really loud and really annoying. So you're saying it could be the fuel pump?

 

Well, if the whining comes from the gas tank than yes, its the fuel pump.

I have over 1/4th of a tank right now. I could put some more in it and see how it goes, but I've never noticed this before in the 5 months I've owned the truck.... and now I'm having problems.

Denali: I have run sea foam through it and stuff like that before, so I doubt the injectors are that dirty.

 

how old are your spark plugs? You might have 1 that is fowledout like i had and my times at the track droped 3/10's just a thought later, kevin

 

Thanks for the reply.

Those are oem plugs with about 2K miles on them. Fuel filter replaced about 3K miles ago.

 

you're just slow because you're slow