I'm trying to think of some of the things that could cause the problem of the filter not being full of fuel.
Not being entirely sure of what system is on the vehicle, am I correct that you are having someone do this work or are you doing it yourself?
No matter who is doing it , does the engine have a primer pump to fill the filter after it is changed?
If the primer pump is leaking air into the system it will allow the fuel to drain back to the tank. And if the fuel pump is mounted to the side of the injection pump with the primer pump one of the valves in that fuel pump may be defective and allowing the fuel to flow back. One of the ways we check this is to place a piece of clear tubing in the suction line and observe if any air is getting into the system. Usually it comes with a performance problem, but the vehicle seems to perform OK does it not?

 

hi hanky, sorry to be a pain reason for no replys as ran out of money! so the situation now is first thing in the morning the car will start fine, drive it about then no start and is like that all day! it will, however start with a spray or a jump. we keep getting low fuel light even though theres plenty of fuel in it. driving us mad and yes we are doing the work ourselves my partner is a self taught man if u know what i mean . any suggestions greatly appreciated