after running for several hours , pulled in for coffee and truck stalled , then wouldn't start . Changed fuel lines 2 days ago , tank to pump . New lift pump and shut off solinoid 3 months ago . Tried priming with no luck . took off fuel filter -emty . filled fuel filter , primed , and it started , till it ran filter dry . tried again , same result . 3/4 tank of fuel . It's my plow truck , snow's coming again tomorrw , thanks

 

Well, since you were able to get it going by filling the filter, then there has to be an air leakbetween the tank and the pump. Did you do a "visual" of the fuel lines yet? Is there a fitting that you had a hard time getting to that may have come loose? Try those and let us know what you find.
Tom

 

Can you hear the lift pump run when you "bump" the starter? It should run for about 20 seconds when you crank over the engine momentarily.

 

The only fittings left are the kwick connects at the tank , I just took the old rubber hose off and put new on the same place , could be them , I'll give it a try

Didn't try listening for pump , I was alone on the side of the road , all I could hear was starter and engine . I'll try that too when I get some help
thanks for the replys

 

The lift pump isn't electric on the 12V engines. The pump is mechanical and positioned down on the block. If you replaced your fuel lines you would have seen it.

Something has come off or come loose. If you can, try to manually cycle the lift pump (push the plunger) and listen if you can hear it suckin air. Otherwise another trick is to gently pressure up the fuel tank from the filler neck and look for leaks of fuel from the lines.

J-eh

 

Since you replaced the fuel lines a couple days ago I would suspect in the wrestling match to install the lines behind the engine that you wiggled the metal lines enough that a line cracked where the hold down tab is welded on. This has happened to me enough times now that I always run new hoses all the way to the tank and abandon the metal lines. You might be able to get it running with a full tank until you have the time to repair.

 

Run rubber line from the fuel pump all the way back to the tank and prime it up. If it doesn't prime then it's probably in the tank. It's still possible the fuel pump may have a bad check valve.

 

When I replaced lines I went from metal line that comes out of pump to the tank all in one peice with rubber ( 10 ft ). At the fuel sending unit on the tank there are two short kwick conn. tubes about two inches long where the old rubber hose attached , thats where I connected the new rubber . Guess it could still be that kwick conn. At the engine end the only metal line are the short ones behind the filter . What would the problem be in the tank ? Is there another pump ?

What would a full tank do for it ?

 

There is a fuel pick up assembly that includes the sending unit for the fuel guage. Inside, it has a coil of plastic tube that goes from the pick up screen/sump up to the top plate where the metal tubes for the fuel line quick disconnects are and the plug for the sending unit. The QD has a plastic lock that pulls out to disconnect and reinstall it to lock it in place. If you didn't get that locked in place correctly it will slowly work its way out with driving causing an air leak. This would be a good place to check if you recently had it apart. I have never done this but some people have removed the QD completely and put the rubber directly on the tube on the sending unit. The QD is mainly for assembly line purposes, so it doesn't matter if it's there or not. In the field there is nothing quick about removing it. The pick up assy has some problems with falling apart and the screws that hold it together protrude in too far and rub a hole thru the plastic causing an air leak usually below 1/2 tank of fuel. This assembly is quite expensive new. I try to repair it if I can. If you have to remove the sender assy, I find the best and fastest way to remove it is by lifting the box up on the drivers side. The reason filling the tank would help is if you have the hole in the pick up tube half way down a full tank would cover it so no air gets in.Good luck


Howard

 

My guess is that you have connected the supply and return lines incorrectly. The truck will run as long as the tank is full, but then stops. Try reversing the connections.
Been there

 

smokee I think you may have hit it . Finally got it running by filling tank and fuel filter. Now it's someplace warm . Took the sending unit out of the tank and can find nothing wrong . Connected a clear tube to the feed and blew in with check valve closed and you can't , which means no holes from screws etc.. Tried sucking and fuel comes up into the hose . Filter looks good . Check valve works
I did try swithing the hoses at the tank when it first happened but I'm not sure I filled the fuel filter to give the initial start.
One thing that still puzzles me is that on the sending unit in the tank the return line also goes all the way to the bottom , which means it should have worked even if the lines were switched. Time to put it together ,I'll let you all Know

 

Put things back together . Eliminated kwick conn. at sending unit and went direct to metal tubes comming out of unit . Took out 5 gals. so I was back to tank level when it quit . Filled fuel filter ,started it up and ran it up and down the road for an hour , no problem . Pretty sure the problem was the switched lines , I hope

Thanks to all for the help , it really makes a difference knowing you're not alone