I recently bought a 99 f-250 with the 7.3 ps. Shortly after I bought it, the truck quit come to find out it ran out of fuel still over a forth of tank on gauge. I put a 2 gallon tank in the back with diesel in it and rode it until it quit again put the two gallons in and drove about a half mile and filled up. OK so heres the question it has run out twice with the fuel gauge in the exacty same spot. When I filled it up it would only take about 18.7 gallons plus the 2 gallons I put in would make aroun 20. Is it possiblethe truck only has a 22 gallon tank and the fuel sending unit is bad ? Or is it more likely the pick up assembly which is pretty pricey. Just seems like it would hold more fuel than that.

 

More than likely the plastic fuel pick up in the tank broke off and no longer goes to the bottom. Search for fuel tank mod.

 

Definately sounds like a cracked or missing pickup foot or duckbill, use this link to imagine, the hutch and harpoon mods are great since the mixing chamber screens will likely clog up causing fuel delivery issues, Welcome to guzzle's In-tank Hutch Mod Web Page

If you choose to go with a "kit" like this Driven Diesel 7.3L Fuel Tank / Pre-Pump Kit or even do it yourself and don't wish to use the large filters you can pick up a NAPA 3007 inline fuel filter for about $3 or 4 dollars.