I may have had same issue, after spending a small fortune changing this sensor that sensor,glow plugs,injectors, fuel rail, mass air flow housing I eventually solved it myself by buying a good agv battery £200 but we'll worth it turns for ever! Secondly a new fuel filter easy to replace...jack car up at the rear. It lies beside the fuel tank unscrews by hand. When replacing make sure you fill the well up with fresh diesel prior to fastening back on.