could be the plugs are gone,the best plugs are the cheap 1s,not the expensive iridium 1s.or could be the fuel pump,if its the latter then its not a good idea to thrash it like that,an 044 pump,fitting kit and wiring should come in around £170,plugs £15.find out from the seller what turbo and housing he had.another thing,your car should be a level 6 ecu,if a level 1 is from a 4x4 cosworth then the top and bottom wires on the throttle position sensor need swapped round iirc.then a good set up to ensure everything is working ok,cheaper than a new engine.good luck.