I just replaced the tank selector valve on my truck. I could feel it and hear it when the switch was changed from front to rear.
If you had a tank overflowing the valve is bad and is returning to the wrong tank. Just because you can hear and feel the movement does not indicate if the inner seals are still good.

 

Your absolutely right.
When I installed an electric pump, for diagnosis purpose's,
because of the high pressure pump,( 8 lb's) it somehow went to the other tank,(overflow)
The tank that it was NOT switched to.
I feel for this "Challe" fellow, but his comment's and problems are not prioritized.
He's all over the place and therefore, with my little knowledge, I can't help him.

 

Thanks!!!
Challe

 

I ran the fuel pressure test (cranking the motor) The pressure checked 7 LBs +or- .My tire gauge was not calibrated to a fine scale. I have a 5 LB mark on the gauge and the pressure was above this mark.

 

Sounds as if your lift pump passes the test. After the truck sits for a while(overnight?) remove the fuel filter and see if it is full to the top. If it is not full, you are getting air intrusion. This lets the fuel run back to the tank, needing an extended crank time to get the injector pump reprimed. The starting and running for 2 sec. that you posted about earlier, would be the truck running on the fuel in the IP, then sucking air. If the plastic caps on the injectors and the rubber lines between them are still painted grey, they are still the factory originals, and are in need of replacing.

 

I think you are on the right track.When the motor dies it is a sharp cut off ,no spits and sputters!!I will pull the fuel filter tomorrow.
Challe:-

 

I would personally eliminate the selector valve myself, thats what I did...I just run on the front tank(its float works) In your case, eliminate the front tank and use the rear. I priced one out @ 264 dollars from the ford dealer, the local parts shops have one that has bullet connection for the valve itself instead of the spade connectors,

 

i disagree with aune163rd, as selector valves aren't that expensive ACDelco U7001 - Valve,F/Tnk Sel | O'Reilly Auto Parts and there are serious benefits to having a second tank. if mine ever goes out, i'm fixing it, not just dumping it.
another option you could have if you don't want to replace the valve for whatever reason, is to simply have a transfer pump from one tank to the other. my old man had this setup in an old international he used to have, and it worked just fine, though in my opinion its inferior to having the selector valve.

 

I pulled the fuel filter and it was full of fuel<> The rubber lines and caps are gray. I have already changed the fuel injectors & rubber hose on the driver side of the motor This corrected the 2 leaking fuel injectors. <Did not change the plastic caps )
Challe

 

You make a comment in post # 26 about the sending unit would not keep the motor from re- starting unless you ran the tank out of gas.I stated in my previous post that my motor shut downs were sharp ,brunt.That is true on my last two shut downs.On the first motor shut down I was driving on the highway and the truck died . I got it off the road ,and the motor re- started and died twice, & then no start. Acted like the motor was starving for fuel. I thought I had fuel in both tanks? I don't know what tank I was running on??
I cannot tie this into the time frame when the rear tank was full after running 100 miles,but it was close. I got the truck started with Wd 40 after the last shut down.Motor would not fire until we added the WD? I have been starting the motor (without WD the last two days,running about 10 min. each time .(Starts and Runs Beautiful)I still don"t have the nerve to take the truck off the property.

 

Sounds like you've got glow plug problems.

Adding WD-40 or ether allows the combustion to begin at low temperatures. Glow plugs are supposed to warm up the engine so that combustion can occur, but without damaging the engine. Starting it with super flammables such as WD-40 and starting fluid can cause permanent damage, so do so very sparingly.

-Matt

 

Appreciate the info.
Thanks
Challe

 

If you read my post, i said the aftermarket ones from ACDelco, have a bullet connnector type port on the valve, ours have spade...every F-series truck I have ever seen a FSV on have spade connectors if you pull the plug out.

 

aune, i see your point there, but what harm is it to simply splice in a pigtail connector to fit the new valve? seems like a pretty simple solution to me, and plugs for those valves are readily available

 

This is starting to sound like an electrical problem, as your fuel system is checking out other than the sending unit, and all that does is read the fuel level in the tank, and they can be a bear to find.
Check the wires on top of the injector pump. They should be snug on the pump. If they are loose the vibrations from the engine coul break contact and shut it down like you shut the switch off. A broken wire could do the same.
You stated that it has started the last 2 mornings with out starting aids, is this correct? If so this is telling me the glows are working. How long does the wait to start light burn for on the first start up, on a cold engine, It should stay on for 10-20 secs. depending on air temps. The colder the air temp, the longer the burn. If it only burns for 1-2 secs., this would point to some bad plugs.