There is another similar thread where the answer was the fuel pump relay, if you haven't tried that, might be worth a shot.

 

i have also swapped out fuel pump relay with new one.Problem is,it will fire up and run decent for a minute then start acting like it is starving for fuel,then shut off.Try to start it again then no fuel pump hum,and when no hum,no start.

 

i put in new ignition switch,and also checked tank selector switch,it checks good.Still fires up and run like it is running out of gas.Whats next?

 

Back to no fuel pump hum.

 

Have you tried hot wiring the fuel pump relay? If it runs just fine with the jumper on then take it off & you can bypass stuff up stream till something shows.

 

yes i just tried to jump the relay,i put 12 volts to it while connected to socket,then put 12 volts directly to the socket and nothing ,fuel pump did not attempt to come on.First thing this morning i went out and turned on switch and there was fuel pump hum,went back 30 minutes later no fuel pump.I crawled under the truck and looked for bad wires,any thing and i came up with nothing.Is it any way i could bypass relay and go to the pump direct and run like that?

 

You could, but assuming the wires are intact between the relay and the pump(s), energizing the relay should make the pump run continuously. You don't want to chop up your harness unnecessarily. The fact that you can sometimes get the hum with the key, if the relay coil was energized, it should complete that circuit & not just for the 30 sec prime.

 

yes i under stand,but off the top of my head could i go to the back of the truck where fuel pump pig tail is and splice in to it,run my wires direct to the battery with maybe a toggle switch in between. just thinking...

 

Hi,
I don't think you have really shown in anyway that it is a fuel problem???

What I would do (because it is doable)

Is get a Haynes Manual and VOM Meter, and run the test on the ignition system!

PIP Sensor, Ignition Control Module, Coil, test spark ect.

Then if that is good you can use the same tools to test the fuel relay and pumps and see what is really going on!

Yea, it takes a little time and throwing parts at it is quicker (I know!) but...

Might as well get used to troubleshooting because these trucks are going to require it from time to time!

Ask me how I know!

http://easyautodiagnostics.com/ford/...-of-articles-1

 

i put a test light to the fuel pump relay plug and i have power,the ecm relay has power,no fuel pump.I am just about to admit to myself,that cheap fuel pump that i installed is dead,i will run a wire to the pigtail close to the pump and if it dont run i'll know it is no good.BUT if it runs and runs strong then what??????