When i leave it over night, it only starts up on 3 cylinders then after about 30 seconds its on all 4 again but very lumpy (at idle and when i drive) like the compression is down on one of them.
There is white smoke for the first 10mins (which is normal this time of year, but it seems more than i usually get), i'm thinking when it's stood up over night water is slowly leaking into one of the cylinders and thats why it's only firing up on 3 and then clears!
I will of course check all my plug, leads, dizzy etc.... but they are all only a week or so old!
There was no oil contamination when i checked, but it was dark so i will check again in a little while, and i dont appear to have lost any water.
So it's a tricky one really, it is possible it could be a ignition problem (plug, lead, or something) but my gut says head gasket.