This issue first started in July of last year, While driving the last 40 miles of a 200 mile trip My box truck started acting like it was over heating. after it cooled a few hours later it started and ran for another couple of miles before I had it towed home. once I got it home it would only run for a few minutes before acting like it was out of fuel. a few minutes later it would start leading me to look into the fuel system, while the fuel rail has good pressure and the pump on the rail and under the door seem to be working fine, the pump in the tank doesn't seem to be working. after extensive research I found in another forum that the pump may only work while the engine is running(I will be attaching a voltage meter later this evening) which it wont do anymore. I am running out of ideas at to how to fix this issue any help is appreciated. The dealer said it is a 5L V8

 

Yes the fuel pump will run for one second each time the key is turned on and will run for one more second each time the computer sees a PIP pulse.
The PIP pulse train comes faster than one second when the engine is cranking or is running so the computer will not time out the fuel pump while the engine is cranking or running.

In other words the fuel pump will run all the time the engine is running and quit one second after the engine dies if the key is still on.

You may have a bad fuel pump but more than likely you have either a bad ICM (Ignition Control Module of the TFI type) or a bad PIP sensor inside the distributor mounted on the stator.

You need to check for spark when it will not run as it sounds like your fuel system may be OK.

 

Absolutely correct, the pump runs for one second every time you turn the key on to pressurize the fuel rail in anticipation of the engine run.
The fuel pump in our vehicles is liquid cooled by the fuel in the tank but it needs +/- a 1/4 tank of fuel at all times to stay cool or else it overheats and fails as you have discovered the hard way, you will have to replace the pump and everything will be fine.

 

The advice about 1/4 tank of fuel minimum is one of the best bits out there for the high pressure fuel systems of an injected engine.

 

pump replaced truck starts now to figure out why it backfires and dies, thanks everyone.

 

A bad fuel pump will cause an engine to "backfire and die" with a lean mix.

 

ok problem solved... added antifreeze/ water remover and she runs like a top. now to do a tune up. thanks everyone!

 

Any ideas how water got into the fuel tank?

 

Either while it had it apart or we had a fueling station (which I used often due to price) that had to replace their tanks a few months back would be my guess.

 

If you haven't already I'd change the fuel filter now---that can't hurt.