running rough

[Greg MacD]

went out to start fd today(haven\'t driven since sunday was running fine then). cranked ok but with a copious amount of white smoke. immediately started running rough. drove it 100m n first gear. second was worse. no backfiring that i noticed r can remember. sounded like tapping. seemed like was going to die out but didn\'t. checked connections of spark plugs, seem ok. boost guage fairly constant. previously engine was very strong but turbos(std twin) a bit smoky. has an apexi power fc and had been tuned. temp abt 3 degree C. someone tell me its not a blown engine plz lol! any ideas? cheers..