diesel bubbling filler neck
 

i've had some fueling issues with my 01 CTD with these mods, hot rod VP44, 175hp injectors, Airdog 150, edge comp, 4" exhaust, SBC Confe clutch, head studs.

truck is running, i happen to open the filler neck, the fuel is bubbling up the neck. Not to the point it is flowing out but obvious that it is bubbling. Tank is more than half full.

when i had the bulk of the above work done, i drove it around at 1/4 to 3/8 full, when i had fueling problems. the injectors were getting starved and truck would stall.

i had to get towed 2x until i figured out that i cannot drive the truck below half full.

the mechanic that put all that work in, said i needed a sump style draw. would this eliminate that or is there another problem lurking with that bubbling of the fuel?

thanks all.

Sounds like the bypass is sending it back kinda forcefully...I wonder what kind of psi it normally runs at....and if it feeds right in at the top of the tank or down the draw line.

Hmmm

a knowledgeable person i know suggested that there maybe a small leak in the return line(?) does that make sense?
there are no leaks or obvious leaks that i can see.

That could draw air in as it passes thru, sure...

if there is an leak, even though even slight, there should be some fuel leaking, showing somewhere along the run.

I don't see any....?

you might check to see where the return line is coming in at and what size return line was used. Could it be he plumbed it fairly high on the filler neck and used too small of a return line? which could explain the bubbling but not the not running below 1/2 tank.
Did mr mechanic do anything to the stock fuel canister inside the tank? On top of the fuel canister there are two hoses the fuel pickup line and the oem return line there is also a third place to put a hose it is actually for auxiliary fuel pickup but just goes into the canister. (this assumes you have the original fuel module not the retrofitted intake pump version it does not have the third port from what I recall) You could plumb the new return line to that and then the returned fuel is going in to the fuel canister inside the tank. You should not need a sump to get your truck to run at below half tank with the oem fuel canister in place.

that fuel module inside the tank is like a canister the fuel pickup is in it as well as the oem return line goes there. It holds fuel within the tank as the tank has no baffles inside of it, the bottom of it is kind of like a cup and the fuel pickup hose dumps fuel into it and the pickup pulls fuel from it. could be the pickup hose inside the tank is messed up?