When i got the truck i don t now what was in the rear tank the previous owner onlly used the front fuel was mistatenly put in the rear ,now it stalls out or over reeves truck is 1992 f150fx

Sounds like something amis in the tank,like pump coming out of the fuel, check the pick up filter screen.

have you looked into the injectors, or injector balance? glow plugs just preheat the cylinders before you start turning the engine over. if the injectors are dumping too much fuel it will run rich and blow black smoke, lean it will dump white smoke, same as if it has an internal coolant leak, but smell different. Ford has had problems with EGR systems on some of their diesels, being an older truck how many miles is on it? and the front fuel tank could have a bad fuel pump, pretty common for them to do what you have described. Also might want to have the timing looked at on it! It ignites off of pressure, and if the timing is off it will adversely affect the ignition of the fuel which will make for hard starts, and poor running. there is a lot that needs to be looked at to figure this one out! could be quite a few different things. Good luck!

Tank needs to be cleaned out and install a new fuel pump.

David Johnson is wrong about that. The Chevy HD dual tank has two sending units, one in each tank , one fuel pump, a fuel pump relay switch and a equalizing pump. If the truck stalls out at 1/2 tank, it is the equalizing pump. That pump, pumps fuel from the rear tank to the front. If the pump is out, the front tank empties, the truck shuts down, the guage reads half tank because the back tank is still full, but the equalizing pump won't pump the rear fuel tank load to the front. Hence the problem you listed above, not a sending unit.

Check your fuel pump in the front tank. The fact that it begins to stall - tells me that the valve is actually working - the front fuel pump just isn't pump fuel.

their are two fuel line at the front of the tank one is the fuel feed and the other is the return line! Now the ones at the back of the tank are for emission you don't want to break or damage those make sure you disconnect all of those line and the is a red connector also at the rear of the top of the tank make sure you disconnect that. And just make sure careful when remove fuel pump it has a tight fit coming out also when your done make sure all your hoses and lines are reconnected and the red ont too! GOOD LUCK !

You need to replace your fuel sending unit, This sends info, to your ecm "computer" witch sends to your gagues. It is located on top of your fuel tank. Best of luck to you.

it may have a seperate pump for the seprate tanks im not sure. it acts to me like its running thaose few miles on fuel left in lines from the back tank. i would start by selcting the frount tank when you put it to bed one night, then in morning have some one turn the key while you listen for a fuel pump if i didnt hera one i would start there. if i heard one check for a seperate fuel filter for the frount tank then check for pluged lines between the two tanks. it has to be someting simple. good luck.

Ok sounds like a electrical problem being an 89 its fuel injected eather 5.0 or 5.8 each tank has its own fuel pump and sending unit a dashboard switch, relay, fuse and switching motor. check your fuel line from the front tank it could be clogged. check for 12v pwr. to the front pump the sending unit will require 4V but not much. as soon as the fuel rail pressureizes the ECM shuts the pump off using the relay. Usually the tank switch goes bad first.

hi your symptoms suggest that you have slight blockage either in fuel line or most likely at point where rear tank fuel line enters the switch over reason ? you say runs ok on rear tank at 55mph? but when demand for more fuel / speed above that pump /engine cannot deliver ? due to narrowing of fuel line (tuberculation) so check flow from r/tank and for any debri inside?