Just been through a few big puddles in 300tdi disco, full sealed snorkel. Engine went really lumpy, idles just. Restarts on key - no power. Made it home just about - smoking white smoke but smells very dieselly not oily exhaust - runs like a petrol with a spark plug out.
Plan A, its to crack injectors one at a time to see which one doesn't make a difference, then check timing belt make sure hasn't jumped then check compression. If bad then head off. What other none invasive checks should I make before needed new head gasket and others etc etc