cuts out after 30 secs

Hi
can any one help
i have a freelander TD4 51 plate

6 weeks ago it cut out, i had the AA tow me to a garage, they couldnt find the problem so they had it scanned(?) and were told to replace the fuel pump which they did and it now starts but cuts out after about 30 seconds then they can start it again after a few mins but it cuts out again, they can not find the problem

can any one give any idea whats wrong so i can pass on any info to the garage

thanks
David

well earthling . . . .wot pump did they change? yer got two low pressure pumps on your model [in fuel tank , and front rhside in engine bay] the one in fuel tank is normally the favorite to go tits. . .both pumps are controlled by the fuel relay [this times out with ign on after 10-15 secs] timing is derived via the fuel pressure switch. . . . .and are fed from the pump fuse , a very good test is to fill the tank up to the brim with doozle the extra height will force more fuel and it should run, if this is the case, then a good indication of faulty pump or pumps or a blocked fuel filter ,hope this helps yer

now thats what i call i reply....a thousand thanks
i think they changed a pump in the rear so that must be the tank pump, but can ask give them some info
i think fillin with diesel is the first step to see if that forces the issue