fuel problems HELP!

has anyone had this problem or know of a possible cause, i am getting air bubbles in my fuel line and its driving me nuts . discovery 300tdi 1996

things iv,e looked at and replaced

replaced the fuel pipe from the tank to the lift pump,--- this didn,t cure it
replaced the sender unit,---this cured it for 2 days then bubbles returned
replaced the lift pump,-- this didn,t cure it

i,ve been told that air could be getting into the return pipes is this true and how could this cause air to be drawn up the fuel line from the sender to the pump? can anyone help me as i,m stumped:doh:

we had this problem after a engine swap , we found out we didnt do up a nut up tight enough on the pump took us ages to find it aswell , had to leave the bleed nipple open on the fuel filter to keep it running ...............

i once had a steering wheel down my pants, that drove me nuts!




sorry, couldnt resist.

robint said:

we had this problem after a engine swap , we found out we didnt do up a nut up tight enough on the pump took us ages to find it aswell , had to leave the bleed nipple open on the fuel filter to keep it running ...............

Click to expand...

sorry forgot to mension i v,e put a peace of clear pipe in before the lift pump and the air bubbles are in the fuel line ,i have checked and sealed all the nuts on the sender unit.

how did you connect the fuel lines to the copper pipes flow and return on the sender unit itself?
I had similiar problems after i had replaced all the same parts you did.

After 3 weeks of arsing about i decided to replace the complete fuel line (flow) with some flexible rubber 6mm ID I think. cost around £15.

Disconnect the old fuel line and both ends and run the new line along the existing one and cable tie it to the old one, utilising the fixings to the chassis will take you around an hour.

I then just pushed the 6mm ID new line straight onto the copper pipes of the sender with no fittings and just jubilee clip the pipe around the copper pipes.

I then inspected the old fuel line and I found 2 pin holes at on of the fitting points.

Again my advice replace the fuel line mate