When it is below 50 degrees outside it is very hard to start and I get white smoke for about the first 3 to 5 minutes after start up. Also the wait light is usually on for 15 to 20 seconds when its cold. It runs great once started and starts just fine once it is warmed up. This is why I think that the glowplugs are the problem. I don't know of anything else that would cause it to start hard only when it is cold outside. Also the other morning when it was only 30 degrees it almost didn't start at all.