bigragu

I remember reading about some of these problems. Can any of you help me with advice to:

I would appreciate all advice from anybody that's fixed this problem. A history of what would cause this would be good also, to avoid a repeat. Let me tell you what I personally am seeing. I hear a low chatter, which becomes very obvious when my tank is at 1/4 tank full. At initial full fill up, the noise is very faint. This leads me to believe it is fuel related. I have done all mods to help against fuel starvation such as the plunger LP and the filter is brand new. Please advise.

Ace

I think it was Flash that said a good way to troubleshoot that, or at least confirm it, was to splice a piece of clear plastic tubing into the fuel line right in front of the lift pump. If you see bubbles, go from there.

bigragu

At suction side or discharge side of the lift pump? What about my concerns about materials needed along with instructions to fix??

loch

As a rule the main pointing finger at a air leak, is the truck doesnt fire right up after sitting as a leak allows air to get in and the truck loses prime as fuel leaks back to the tank.

Most leaks occure at the tank or by the pump, there are rubber hoses that connect to the steel lines and they get old over time. Just a note, do not use gasser fuel hose to replace them, diesel doesnt like it, use tranny hose.

Its a tight fit but you can reach the hoses on top the tank from underneath, you just have to wiggle a bit.

This chatter is coming from where ? if you can tell. Does truck start up ok after sitting over night ? If it starts fine, id lean towards the pump itself,

Diesel Junkie

Mine would loose prime overnight, and more commonly if not run for a few days but was intermitent, and slowly got worse until it was every other day.

I searched for fuel/ai leaks every where, but when i converted to a piston lift pump the problem dissappeared. It also smoked less after the piston pump was installed. My problem was also releated to fuel level in the tank,, The lost prime was most likely when the tank was low.

My truck ran fine after it was started though...

If you have a problem while the truck is running, I would think that it is most likely an air leak. There is actually suction on the line while it is running... i have heard of the fuel pickup tube having leaks inside the tank.

Ace

It's just a troubleshooting step to confirm whether or not you have an air leak somewhere between the LP and fuel tank. Couple hose clamps, a 5/16 brass splice from any hardware store and a piece of this is all you need:

bigragu

My truck starts OK all the time, no problem. I apologize if I left that part out. Like I said the faint chatter is less faint and more evident as the fuel tank empties out. At fill up, the chatter is faint to none at all.

I thought it was the Power steering pump, and that was replaced because of the constant leaking. Now that all is good there, I am still baffled with the noise still being there. It was just the other day I noticed at a 1/4 tank that it was very evident, so after the noise went down after fill up, this is what led me to posting this problem and seeking help.

bigragu

My truck runs fine, just want to avoid the innevitable.

loch

Try to determine if its the fuel pump, use a dowel or long screw driver, touch the pump and cup you hand around the other end and listen. Its a poor man stephiscope, if noise seems not be there just listen around for it, stay away from fan, it hurts ,,,,dont ask how i know

Tommy93w350

My started sucking air at the inlet connection on the lift pump. The truck had hard starting, idled low, and quit on the side on the road. I bled a few injectors to prime it and and it started up and limped home. The odd push on connector has a O-ring type seal. I found a new one at AutoZone and spliced the lines together.
I reccomend replacing this OEM setup with a barbed nipple. The OEM setup has a very small opening for fuel delivery.

bigragu

Thanks for all the advice. Everyone with this problem all has starting issues. Mine has no issues w/ starting...ant other suggestions?

JimmieD

It seems like the best suggestion has already been given: find out WHERE the problem is. Once you do that you've got a better shot at finding out WHAT the problem is! You can use an automotive stethoscope, or a piece of rubber hose to your ear, or a long thin screwdriver or rod. The screwdriver/rod has the most potential danger from fan blades. All will telegraph the noise long distance to your ear as you poke around.

With any of these you can precisely pinpoint the exact area making noise and no doubt that will reveal what component is failed or causing problems. Please be careful as this is somewhat dangerous on a runnig engine.....

bigragu

I wish there was a way to do the stethoscope thing while driving ...That's when I hear it, not under the hood....I'll try it again

JimmieD

I just re-read my own post and was surprised to see that it came out kind of insulting! NOT WHAT I INTENDED, the words didn't come out right...

Seems like if it was the fuel lift pump it would be noisier parked than running. I wonder if it's a u-joint/driveline noise that's also telegraphing through the fuel tank somehow when fuel is low? that is, tank magnifies driveline sound in some way. Might be worth getting under there and checking drivelines etc. That's all that comes to mind here.

bigragu

Stick and stones may break my bones but words will never hurt me; that is unless you call me a pencil neck geek or something, and that is when I turn greenish.
You may have something on the driveline thing. I am making my list, checkin it twice, with ya'lls advice.