I have a similar sounding problem read all your posts hoping for a solution for myself. I dropped the tank pulled the pump jumped it to 12v it ran non stop.
plugged it back in turned the key it ran @2 sec then stopped.
I checked voltage when pump is plugged in turn key 14.2v @2sec then no power. I tried a new pump same story. When unplugged key turned on power @ 14.???? stays on plug in pump power turns off. Changed relay no diff.

Before i dropped the tank I got it to run with starter fluid it ran a couple of days the wouldn't start again thought I was out of fuel add some it started ran a couple of days kept tank full, the again wouldn't start so I figured it the pump.

Now i don't think so, but don't want to put the tank back until I know what's the problem.

Thanks in advance if anyone is still reading this dead thread?

 

The result you are getting is OK.
The computer allows the fuel pump relay to become energized for approx. 2 seconds when the ignition is first turned on.
When an attempt is made to start the vehicle the RPM signal goes to the computer and it will energize the f/p relay . If no attempt is made to start it as appears in your case, no RPM signal, no f/p.

 

it sounds like you might try to get the codes from the eec it might tell you what went wrong with your truck then again there are some things that it won't when there isn't a
problem with any of your sensors. ain't that right Hanky?

 

Yes and no !
That's a loaded question.
The reason I gave this answer is;
For example, if you had a defective fuel pressure regulator (not a sensor) it could over fuel the engine ,but the O2 sensor would/could generate a code and not be defective itself.
Soooooo, before I dig myself deeper, I believe you are in the ball park.

 

good boy Hanky

 

Thanks for the input I just figured if the pump didn't run when the key was turned on something was wrong. At least 4 times on different occasions it would stall or just not start, then a few hrs or a day later it would work just fine. Last time after making sure it was full it wouldn't start so I decided to change the fuel pump. But since I have it out and tested it I'm no longer sure it's a fuel pump.

How can I be sure the fuel pump is good or bad?

 

I jumped the relay pump ran non stop, so hooked the pump up turned key 2 sec then it stopped continued to turn key to crank starter pump started to pump again but since the tank is out I don't know if will actually run and if so what is my problem really?

Where is the fuel pressure regulator?

 

You never told us the year and model vehicle you are working on.
Two suggestions, never run the pump dry. Always have gasoline pumping to keep it cool and lubricated. Consider using a Ford dealer supplied fuel pump. They run better and last longer.
While you have the tank down just make sure you have good solid connections to the pump, a good ground connection is very important.
Not knowing what year vehicle you have will try to explain differences.
There were 2 types of systems used.
Return type where the Pressure Regulator is located under the hood on the fuel rail and returnless type where the pressure regulator is located on the fuel pump module in the tank.

Do you know how to check for spark to the plugs?

 

Sorry, 96 E 150 with 5.8 single tank midship. I've got an idea about checking spark after I take the inside cover off I'll do that and look on the rail for a pressure regulator as the pump assembly doesn't appear to have one and I did run the pump in a bucket and since it pumped I guess I don't need a new one.

I'll post my spark results when I'm done.

Thanks

 

I have spark, I pulled a plug wire put a screw driver in it held it close to the exhaust manifold cranked it over and had a red spark.

I looked along the rail and didn't see anything that looked like a pressure regulator.
Is it before or after the fuel pump or is it something with the in tank assembly that I don't recognize?