I had triple up the problems. Several lads complained because of lots of white smoke on startup and only a couple of cylinders working until the engine got warm. Well, I had 4 cylinders working, the glowplug lamp was blinking, and lots of white smoke. Turned out to be both bad plugs, bad wiring on the rails AND a loose/full oxide.

So, check all your contacts - are they lose/oxidized? Are the relays jumping around not being fastened?
Check your glowplugs and the rails.

It should not be too difficult to spot the problem!