C20let running problem

[scorge01]

Ok guys I'm looking at buying a mk3 Astra turbo it's quite far away an has a running problem so trying to work out what's up before I run out an waste my time it runs lumpy on idle doesnt rev well blue smoke an management is on the oil an water is fine not mixed an no creamy gunk about doesn't knock or anything just misfires?
I thought turbo an mabbe needing plugs an leads as sat for a while any outhe ideas?

[Jeff16v]

could be loom, sensors, fuel pressure , the smoke could turbo oil seals or overfill, or too much oil pressure caused by blocked breathers, can you ask them to flash the codes?

if they dont have any error codes, i'd avoid