hi i have a mk6 ford fiesta silver 2004 model recentley the bottem end failed so ive just bought and fitted a low mileage replacement (same engine code) on start up the engine refuses to idle soon as you release the throttle it dies , we have used most of the original sensors and parts (pas pump,crank sensor,throttle body, vacuum sensor,alternator,coil pack,) as the repacement didnt come with these, i think the alternator needs replaceing as the battery light stays on and after tested its only produceing 11 volts?, could this be the problem? all warning lights are lit up on dash (engine ,abs,airbag) the car idled fine on original engine, i performed a diagnostic and only 2 things poped up was "emisions above theshold" and" heater control valve" any help much appreiciated thanks will

Did you swap over the idle control valve? Sometimes called an air by-pass valve. Should be attached to the throttle body.