Freelander 1 won't start intermittently

I have had trouble with my Freelander 1, TD4 2006. I live in Spain and bought it a year ago in the UK and brought it here. It worked fine for 8 months, and then suddenly it conked out, as if it had run out of fuel. I put some more diesel in and it started but was missing all the way home, (3.5 hours). To cut a long long story short, my mechanic has cleaned up the whole fuel system, replaced various sensors, replaced the connector to one sensor and now it can run perfectly for a week, and then suddenly not start. I have had to call for a breakdown truck 3 times. The last time it wouldn’t start until Easy Start was sprayed into it, then it started and ran as long as Easy Start was being sprayed into it and then would stop. Obviously some sort of fuel issue. Got it back to the mechanic’s garage, by breakdown truck, after which it started and ran perfectly. The mechanic did nothing to it at all. The only thing that happened was a fair bit of jolting as it was loaded on and off the breakdown truck.

The mechanic’s advice is to get rid of it! (and pass the problem on to someone else!). His stance is that because the fuel filter had never been changed, the whole fuel system has got crud in it, and you’ll never be able to get rid of all the crud. I can’t believe this and just think there is something fundamental he is not able to get to the bottom of. He is a young Spanish guy. He is great for changing components and things like that, but I don't trust his diagnostic ability. My Spanish is bad and his English non-existant.

The engine has done 110,000 miles, doesn’t smoke or use any oil or water and when it’s running, it runs as sweet as a nut.

Any suggestions would be greatly appreciated.

Can you hear the fuel pump running at the back of the car (UK drivers side rear wheel arch)