checked fuel pressure

[cmasonrun]

i did a leak down test, and when i turn the fuel pump on, the motor primes, and when i finally get the x started it runs fine, but when i turn it off it loses pressure instantly, within 5 or 6 seconds there is zero pressure...someone suggested the one way valve, where is the one way valve and is there a different name for it?

 

[aldive]

When I have seen these symptoms, I have had to replace the fuel pump.

Good luck ....

 

[cmasonrun]

is there a one way valve somewhere in the fuel system? or is it in the fuel pump or in the fuel pressure regulator?

 

[aldive]

My '99 SOHC does not have an FPR.

 

[cmasonrun]

bump

 

[bjorkmae]

Your 99 has a FPR, its just in the tank. Ford did that because it is cheaper then rail mounted fpr. I prefer rail mounted for ease of repair and modification. If you run out of gas with a FPR in the tank it takes forever to get the car started again because you have to wait for the air in the line to be cleared through the injectors, with rail mounted FPR you just turn the key to on a few times for the fuel to prime through and your done.

 

[cmasonrun]

what could it be guys?

 

[cmasonrun]

any one?

 

[Fordmandan87]

as it was stated before replace your pump there is a one way check valve in the pump itself so replace the pump

 

[MrShorty]

Fordmandan got it, the check valve is part of the pump.

 

[rwenzing]

Ford did that because it is cheaper then rail mounted fpr.

Actually, Ford did it to reduce evaporative emissions. A returnless fuel system does not pump engine compartment heat back to the tank via the fuel like a return system does. From a total cost standpoint, a returnless system costs as much or more to develop and build compared to a return system.