i have a 2000 f150 truck stopped running could not hear the fuel pump prime checked all fuses and relays put a new fuel pump in today and its still not working can somebody help

 

Check the inertia switch.

 

i did its ok

 

So, the engine will crank but not start ?
Have you checked for fuel pressure, at the valve on the fuel rail. ?
Did you also change the fuel filter ?

 

yes changed the filter and theres no pressure at the fuel rail

 

You'll need to verify that there is power at the fuel pump.

 

Got power to pump took the pump out and hooked to the battery and it works

 

You’re going to have to check for power at the harness itself. It’s possible the plug at the tank end is damaged. Maybe someone with a manual can chip in a schematic.

(That’s a lot of work to do if that’s all it turns out to be...)

 

have power at the connection.could it be the crankshaft position sensor

 

Possibly, Do you have any codes ?

Although, if you have power at the pump it should prime. I don't think any other sensor is required for the pump to prime. Only need to turn on the ignition without starting. Someone will tell me if Im wrong.

 

Crankshaft position sensor won’t keep the fuel pump from cycling at “key on” time.

Having power at the fuel pump connector at “key on” time is good.

But does the ground at the fuel pump connection get pulled to ground when the PCM cycles the pump for three seconds at “key on” time?

 

i know this is going to sound stupid but for the last 2 nights when the is colder outside the truck will crank and run but when it a little warmer outside it wont

 

So if it will start then the fuel pump is working. It primes and there must be fuel pressure. Might help to know what the fuel pressure readings are. Have you checked for codes ?

 

only code showing is the o2 sensor

 

The O2 sensor should not stop the engine from starting. Other sensors are apparently OK. It's important to eliminate the fuel pump as a variable.

Earlier, you indicated the fuel pump could not be heard cycling on. It would be very helpful to know if the fuel pump is consistently cycling on in the "key on" position.

If it is consistently cycling on, then it would be helpful to know what the fuel pressure is when the engine starts and when the engine doesn't start.