got a mk3 cab with a 1600 cvh turbo engine, stg2 turbo, cam, chipped etc... runing 198bhp. recently went to run it lots of white smoke and flames unable to get any power when acelrateor pressed like its missing baddly , it starts ok but once it warms up cuts out, though it could of been a head gasket, had a spare head so c the head was changed and pistons where checked and ok, started after this but once warm the same problem, might be over fuelling but the fuel metering head has been changed and no diffrence any one got any ideas ??? get pretty desprate car been of the road for a while. not that great at the mechanics side but slowly learning on this car so can any replys be in simple talk sorry

thanks
steve