nickleahy23

iTrader: (1)

Well since I swapped the motor ive had thise noise/vibration coming from the fuel rail/fuel lines. I thought it was kinked lines because they were messed up..I just redid the fuel lines and now its still there..i can hold the supply line and there is no vibration or noise, but when i hold the return line i can feel it vibrate and it makes a noise like its restricted.

I replaced the metal line that connects the 2 fuel rails when I did the fuel lines last week so it isnt that.

only thing i can think is that its the fuel pressure regulator. I swapped the one from my 5.3 onto the 6.0 when it was on the engine stand..it was aftermarket so maybe it doesnt work quite right..other then that, what else could it be? I can feel it vibrate the whole fuel rail but its faint everywhere besides the return line right off the fuel rail..

because of this, it idles down super low once and a while, it will even die occasionally..

hirdlej

iTrader: (31)

Are u sure you're just not feeling the tapping from the injectors?

nickleahy23

iTrader: (1)

YaYa I'm sure...it makes the truck stumble n run like ****..its only the return line that I can feel it in

its loud too..from inside i can hear it clear as day..it sounds like a squeaking of some sort from through the fire wall

hirdlej

iTrader: (31)

Vacuum leak at the brake booster hose/fitting?

nickleahy23

iTrader: (1)

nope lol..ive checked everything possible...if i grab the fuel line that goes between fuel rails, i can feel the vibration...i can feel the vibration where the 2 lines come into the fuel rail, but then once they split (since i ran new seperate lines, so they dont touch), i can feel the return line vibrate/pulse really bad..

now my fuel pump is being wierd and about to go out, but i dont think thats the problem, since the vibration is only on the motor side, i cant feel it in the lines under the truck..

im gonna try swapping the FPR and go from there..if not that, its either the fuel rail of the injectors..

It makes the wierd *** noise when i prime the pump by turning the key foward but not starting, so i know its fuel..its like i can hear the fuel coming up the line, into the rails, then back out the return..

i have hard starting as well..i have to prime it every time...it was fine with the old motor, only started with the 6.0, when this problem started..fuel pressure doesnt stay after running either..i hit the schrader valve, and nothing comes out

MikeGyver

iTrader: (5)

It must be touching the body.

nickleahy23

iTrader: (1)

ya, the return line is running down the firewall....its just confusing..i think ive narrowed it down though, so ill just eliminate things i guess lol

MikeGyver

iTrader: (5)

I guess I should have elaborated: You know it's not supposed to touch the body, right? It needs to be isolated in rubber, or it will make noise like you describe. The firewall seems to amplify the noise of anything that touches it.

Burgundy&TanMan

The line vibrating? I dont see how that should make the truck run any different as lond as the fuel psi stays constant. But hey I guess anythings possible.

nickleahy23

iTrader: (1)

well it made noise before i ran the new lines..they were hooked to the trans like stock...and you can hear it from in the engine bay..

when it makes noise, is when is stumbles/idles like ****...

i can hold the supply line and i dont feel anything, but if i hold the return line, it vibrates like crazy....something is restricting it in the fuel rail/fuel system...

ill be driving through town at say 30...at a low rpm and constant speed..it will start sputtering and make that noise, then i give it gas and it goes away...

if im at idle and its doing it in park, ill give it gas and it goes away...

its really weird as hell

and i should say, i havent gotten a chance to test the psi at key on, idle, and load....im trying to find a gauge to do so

i know my fuel pump is funky, but its been the same since the 5.3, and the 5.3 never acted this way