Starving for fuel???

[Mustangflyer]

Hey guys,
A few weeks ago I was coming home from a weekend trip to the Glamis sand dunes (which btw, the Military 37s did AWESOME in the dunes), leaving a border patrol checkpoint when the truck acted like it was running out of fuel. I was on the rear tank (a new 38gal one) at 1/2 tank of fuel. I pulled over with it still stumbling when the truck shut down. I thought maybe all the bouncing around in the dunes might of gotten the float stuck somehow, so I switched the tanks, and after 20 seconds or so of cranking, VOILA the truck started. Drove fine the rest of the 200 mile trip home.
So I drove around on the front tank until I finally had time to inspect the rear. Problem was there was AT LEAST half a tank of fuel still in, so I quickly said forget pulling it down. I switched back to the rear tank, started the truck, and ran around all weekend... Maybe 30 miles or so, before the truck did the exact same thing, acting like it was starving for fuel.
This time, I was able to switch tanks before it died, ran, and switched back, and it hasnt done it for the last 20 miles or so.
Do you guys have any idea what it could be? I was trying to find a diagram of how the fuel selector motor works, but haven't had any luck yet( I was thinking possibly a relay going bad?) Any input is appreciated! Thanks again guys!

[bigcountrysg]

run the tank down to E then drop it and then remove the tank. I would bet your fuel sock on the pick up tube may need replacing.

[Mustangflyer]

I have probably less than 4000 miles on the strainer in the rear tank. Do you think if it was the strainer/sock it would be a constant issue?

[bigcountrysg]

Originally Posted by Mustangflyer

I have probably less than 4000 miles on the strainer in the rear tank. Do you think if it was the strainer/sock it would be a constant issue?

Well if you have less then 4000 miles on the strainer did you replace it previously or have you cleaned the tank out.

The other issue can be the switch valve between the tanks.

[southend]

Originally Posted by Mustangflyer

I have probably less than 4000 miles on the strainer in the rear tank. Do you think if it was the strainer/sock it would be a constant issue?

I will say that my 95 7.3 with around 250k started doing the same thing to me. I lifted the bed, pulled the pickup tubes and found the strainers were desintegrated and laying in pieces in the bottom of the tank. There was also about 3/4" of sludge, rust, and dirt in the bottom of the tank. I took the tanks out and cleaned and dried them and bought two new strainers. I haven't had a problem since then, 308k miles and going. If you put your hand on the switch and get someone to move the switch, you should feel and hear it click, if not check the connector first. I would also suggest disconnecting the fuel lines inlets and outlet (it is a bit messy) at the selector switch and blowing low pressure air through the valve with each tank selection to make sure you are getting proper flow. I also ruined the mechanical pump by stupidy trying to pull start it while my brother was pulling me back to the house before i did any trouble shooting. It is apparent that the problem lies in the tank pickup tube, strainer, or selector valve. hope this helps, good luck.

[Mustangflyer]

Sorry , should have included more information, the strainer was replaced roughly 4000-5000 miles ago when I upgraded to the 38 gallon tank. So the tank is new, pickup tube and strainer. This is why I was leading more towards the selector valve . Thanks for your ideas so far !

[elrojo63]

check the vent tube. It could be clogged and you could be vaccum locking the tank