Hello, I have a 1999 Ford F-250, 4.6 Ltr. manual transmission. No start, no fuel. Replaced fuel pump, still no fuel. Checked power wire going to the pump with a test light, when I turn the key to start it, there is power for about a second, then nothing? Same thing at the inertia switch. I believe I finally found a correct fuse/relay box diagram. I suspect the fuel pump relay? The diagram I have shows that relay in position 301, full size relay. A fuel pump fuse #10, fuel pump relay fuse #18. Any other ideas?

 

When you turn the ignition key to the run position the PCM powers the fuel pump for about 1 to 2 seconds then powers it down until it sees a CKP signal. The CKP signal indicates to the PCM that the engine is cranking, so it then powers up the fuel pump to start the engine.

 

When you turn the key to run the pump only runs a couple seconds. That is the way it works. Do you here the pump run?

 

there may be a Schrader valve on the fuel rail above the motor. IF you hear the pump run for 2 seconds when you turn the key, see if there is pressure at the Schrader valve. If you have power and the pump don't run, then you have bad pump or bad ground.

 

As stated the pump only runs a second or two.
To see what it is doing, put a gage on the rail test port.
Switch the ignition on and off several times.
The gage should come up to pressure of about 35 psi.
Otherwise your looking for a problem that is not there.
The reason it works this way is to pre charge the fuel rails ahead of cranking for faster startups.
Second reason is to stop the pump from running if there is a fuel leak that could feed a fire.
The crash sensor is there for the same purpose.
It has worked this way since 1985.
If the motor does not start with good fuel pressure, you have some other issue.
Good luck.

 

That makes sense, even though I've never ran into quite this situation. I could see Ford not wanting the pump to run, if the computer isn't seeing a crank signal. I'm going to try replacing crankshaft position sensor today. I will post my findings tonight. Thank you again, pdqford.

 

Why are you not doing the testing to see what's going on but going into guessing by replacing parts?
It may be the connector on the crank sensor is intermittent.
If there is no signal from the sensor, there will be no spark or fuel, at cranking time.
The pump runs due to PCM powers up at key on, not from the crank sensor.
Good luck.

 

I have done testing. There is no fuel pressure. There is power at the fuel pump when the key is turned to turn over the engine for a second. Please read the entire posting before asking me if I did testing. My only other question is if the the crankshaft position sensor is bad, why does the motor run when I spray gumout in the throttle body?

 

Your confused.
If the motor runs with spray, IT'S not the motor or any part on the motor.
The pump is faulty if there is no pressure.
Change it end of story.
Why make it so hard?
Good luck.

 

Blame it on the owner. She had lost her key, went and had a new key made, the key maker recoded everything, in case someone found the lost key, they couldn't use it. She had found the key, and was trying to use that. I told her to bring me her spare key, started right up.

 

You should have told us the THEFT light was flashing like mad right in front of you... we would have immediately zeroed in on the anti-theft system.

 

Nah, dem little tings don't mata!
Good luck.