Fuel Gone

[Joshpow]

I got an issue with the ol 72 I wan opinions on. When I let it set for a while, it is hard to start. I checked the fuel filter I added between the pump and carb this evening to find it empty. The line has been drained. I don't see a leak in the line anywhere. My question is what are some ideas to check? I figure the float may have stuck open and be causing it to do this. Does that sound legit? If I have a leak between the tank and pump, will it drain the line after the pump? Please help!!

[fordman]

do you have a vented gas cap? maybe the fuel is getting sucked back into the tank. but if you have a 72 i think the tank is vented from the factory. maybe the vent is clogged.

[Joshpow]

That is an idea. I do have a vented cap. The problem only showed up in the last few months. Until then everything was great. I got an Edelbrock carb if that brings an experience to mind for anyone. I will check the vent on the tank to see if it is open. My carbon canister is taken off and the line is removed back to where the line comes out under the cab.

[Doug Comer]

If you can, check your fuel pressure. In my own experiences when a fuel pump begins to wear it won't hold the fuel from the pump to the carb. Hope this helps. Doug

[Joshpow]

Thanks for the input Doug. I don't have a gauge. How else could I tell if the pressure is low? The filter stays full while running and for several hours after I cut it off.

[saidyene]

I had this same problem with a truck the other day. It ended up being the fuel pump. If these trucks have a similar setup to the one I was working on it will hold fuel for a while then drain out. We also had the problem of the pump not pushing enough fuel to keep the truck running if you got on it. that may have more to do with this trucks setup after the pump.

[Banjo]

you may want to also smell your oil and check the level. I've only encountered 2 fuel pumps failing and in both cases, the car might crank and run but wouldn't pull a hill or up a driveway. And, in both cases, the oil was gas fouled and oil level high, because gas was venting to inside the crankcase, not backing back up the fuel line into the tank. Can lead to bad bearings....
The little piece of fuel line under the cab which runs from gas tank to inside frame can also be a hidden source of trouble as it's hard to see cracks, and it's also like leather when aged and hard to cut off too. just random thoughts.

[george worley]

I had the same thing with my trk if it sits a couple of weeks. It did it even with new mechanial pump, so I put an electric pump on it and removed mech. pump and used a block off plate.Wired electric pump direct to battery and used a toggle switch and 10 amp fuse.Now I just turn on pump be fore I start engine, works great also good theft device. You have to remember to turn it on and off or you will drain your battery. I may change mine to hook up to the igniton switch, but I still will use the toggle switch for anti theft.

[Joshpow]

Cool guys. That might explain my WOT hesitation here lately. Not enough fuel = not enough go! I may have to put on a pump. I am sure it aint going into the oil through the pump though. With an electric, will I need a regulator for the fuel pressure?

[Joshpow]

Cool guys. My truck isn't expensive to fix the pump on. I believe they cost $29.99 at Autozone. I'll check at NAPA for a better pump later.

[Joshpow]

Cool fix there. Mine takes hot start problems by spells. I'd sure like to fix that.

[ezernut9mm]

i have the same problem. changed the fuel pump and it still empties the inline filter, but there have been no drivability issues so i pretend it is not happening.

you can see it unloading in the vid.
http://s4.photobucket.com/albums/y150/e ... IM0351.flv

[thebannister8]

could be reverse flow back through a worn fuel pump diafram

[ezernut9mm]

that's what i thought so i bought a new fuel pump and it still does it.

[fordman]

chris what kind o ffuel cap do you have on your tank? is it vented. i tmight be sucking the fuel back intot he tank because of back pressure.