It sounds like you may be pulling air through the tank selector valve. You can pull the lines off the valve and only hook up one tank and see if the problem goes away. If it doesn't move the lines to the other tank. Some have replaced the valve with two 3 way valves to isolate the tanks.

 

isnt that the solenoid on the ip the wire farthest to the firewall?how would i go about checking that see if there is power when the key is turned to accessory?and at this it cant be air coming from the tanks cause there is a hose running from my new electric pump to a can of diesel.what i dont understand is why am i getting air out of the ip at the return line fitting?

 

It's the connector furthest to the driver's side on the IP.
Turn on the key, disconnect and reconnect the wire/connector and listen for a "click", if it clicks it's working.
It's the switch that shuts the fuel off and kills the motor when you turn off the ignition switch.

 

oh ya i tested it and its workin i keep rechecking it just to make sure haha

 

The one closest to the firewall drivers side is cold engine timing advance.
The one closest to the radiator drivers side is the fuel shut off solenoid.

When you turn the key to Acc, there should be no power on any of the IP terminals.
With a cold engine and the key turned to ON, there should be power on all three of the IP terminals.

You can test that with an automotive test light or multimeter.

If I am understanding you correctly, you are now running a fuel line from a can of diesel to an electric pump, then through an inline filter and straight to the IP bypassing all of the stock fuel supply lines.

Did I understand that correctly?

 

the only stock line is the one that runs from the filter head to the ip i put a hose adapter on the end of it to kook up the rubber fuel line to it.you are correct that is what im doing and i still get no ignition the exhaust isnt even smoking so for some reason fuel isnt getting in

 

well i tracked it down finally i think i had a bad battery on the drivers side and the shut off solenoid was only getting 7.4 volts so i ran a wire from the good battery to the solenoid and it fired so i went and bought a battery and im still only getting 7.4 voltsb so what could cause this?should i just wire it ti a toggle switch as well but the thing is i dont want to overload it with power i dont know if it can only handle 9 volts like its suppose to be getting

 

You got me on that one.
I'm sure Dave or someone will know.

 

well i got it home ran a toggle switch to the cab for the fuel pump took the hose out of the can of diesel hooked it back up to the line to the tanks and still not drawing fuel up.il tell ya what this is never ending.i looked for airleaks along the lines and reversed the pump to pump fuel backwards through the lines to try and find leaks.and nothing so im guessing both pickup tubes in the tanks fell off at the same time or my selector vavle is junk but i can hear it clicking what do you guys think?

 

Does the fuel level change when you switch tanks?

The gauge connection is the last one made on the selector valve when you switch tanks.

There is a possibility that the selector valve has internal problems, but that seems to be a very rare problem.
Usually when they go, they just quit running at all.

 

Can you hear the tank selector valve operating when you change tanks? You should hear a zipping noise from the valve. If no noise there is a fuse in the under the dash fuse box. Dont remember whitch one. It controles the valve and the fuel gauge.

 

You might have more than one prob at the same time ... Foamy fuel is a good indicator of air getting in somewhere ...

As to the pressure problem ... You mentioned that fuel was going from one tank to the other ... Does anyone know if there are one-way valves that prevent that from happening?

 

i can hear the valve switching but im wondering if there is something internally that went out causing it to leak air from one tank possibly.and maybe the other tanks pickup tube fell off and its drawing air and creating a vaccum to pull fuel from one tank to the other.should i just blow a bunch of cash and fill one tank up and see if i can figure something out?

 

For that to happen, the valve would have to be bad.
I ran my truck for almost an entire summer with the rear tank removed, just unhooked the fuel lines and pulled the tank.


I can see you having a problem with the pickup tubes, very common problem.

With unbaffled tanks, the fuel sloshing around while driving breaks the bottom plastic piece off after some time, which usually lets it run out of fuel at about 1/4 tank.

I have also seen cracks in the metal tube higher up, it usually takes air pressure to find these cracks.

Usually if that is the problem, a piece of fuel line can be slid up over the suction line and clamped in place with a small hose clamp.
Be sure to cut a V in the bottom end of the hose so it can not get sucked against the botton of the tank and cause more problems.

I have also seen holes in the fuel line fittings on top of the sending unit.

With a stock bed on, there is no way you can wash the salt and mud off the top of the tanks, so it just lays there eating at the metal every time you drive on a wet road.
Same can be said for the seam around the tanks, common place for the tank to start leaking.

 

sounds like i have alot of options so should i syphon one tank into the other and see what happens and see if i can draw fuel up? or just pull the bed